iPhone Error and Warning Messages List | Causes and Solutions Explained

Charging, Lightning, and USB-C

Message / Symptom	Main Cause	Solution
Liquid Detected	There may be moisture on the Lightning or USB-C connector or cable.	Disconnect the cable, hold the connector facing downward, and allow it to air-dry. Avoid wired charging until it is completely dry.
Liquid Detected in Lightning Connector	Moisture has been detected inside the Lightning connector.	Disconnect the Lightning cable, allow the connector to dry, and then reconnect it.
Liquid Detected in USB-C Connector	There may be moisture inside the USB-C connector or on the connected cable.	Disconnect the cable and allow it to air-dry. Avoid USB-C connections until it is dry.
Charging Not Available	Possible causes include liquid detection, dirt in the connector, or a faulty cable or charger.	Check the connector and cable, and try another charger or cable.
Charging On Hold	Charging has been temporarily paused because the device temperature is too high or too low.	Move the iPhone to a location with an appropriate temperature and wait until the device temperature returns to normal.
Slow Charger	Charging speed has decreased due to insufficient charger output or the connection method.	Use a power adapter with appropriate output and a compatible cable.
Low Battery	The battery level is low.	Connect the iPhone to a charger and charge it.

Accessories

Message / Symptom	Main Cause	Solution
This Accessory May Not Be Supported	The accessory may be incompatible or faulty, or the connector may be dirty.	Reconnect the accessory and check the connector. Also try another compatible accessory.
Accessory Not Supported	The connected device may not be compatible with the iPhone.	Check whether the product is compatible with iPhone and use another cable or accessory if necessary.
Unlock iPhone to Use Accessories	USB accessory connections are restricted while the iPhone is locked.	Unlock the iPhone before connecting the accessory.
Cannot Use USB Accessory	Possible causes include insufficient power, an unsupported device, or a poor connection.	Reconnect the device and check compatibility and the power supply.

Battery

Message / Symptom	Main Cause	Solution
Important Battery Message	A problem has been detected with the battery condition or replacement part.	Check the battery condition in Settings and request an inspection if necessary.
Unable to Verify This iPhone Has a Genuine Apple Battery	The iPhone may be unable to properly read the battery information.	Check the repair history, and if the issue does not improve, consult Apple or an authorized service provider.
Your Battery’s Health Is Significantly Degraded	Battery performance has declined due to long-term use or other factors.	You can continue using the iPhone, but consider replacing the battery.
Unable to Verify Battery	This may appear when the iPhone cannot properly verify a replaced battery.	Check the repair history and request an inspection if necessary.

Temperature and Overheating

Message / Symptom	Main Cause	Solution
Temperature Warning	The device temperature has increased because of direct sunlight, a hot environment, heat generated while charging, heavy processing, or other causes.	Stop using the iPhone and allow it to cool naturally in a place away from direct sunlight.
iPhone Needs to Cool Down Before You Can Use It	The internal temperature of the iPhone has exceeded its usable range.	Turn the iPhone off or stop using it and wait in a cool place until the temperature decreases.
Flash Is Disabled	The device temperature may be high, temporarily restricting the flash function.	Stop using the iPhone and allow the device to cool down.

Storage and Insufficient Space

Message / Symptom	Main Cause	Solution
iPhone Storage Full	Photos, videos, apps, and other data have used up the device storage.	Go to “Settings” → “General” → “iPhone Storage” and remove unnecessary data.
No Storage Space Available	The device does not have enough available storage space.	Delete unnecessary photos, videos, downloaded files, apps, and other data.
Unable to Save Photos or Videos	Insufficient storage or a temporary problem with the Photos app may be the cause.	Check the available storage space and delete unnecessary data if necessary.
iCloud Storage Is Full	You have used all of the storage included in your iCloud plan.	Delete unnecessary iCloud data or consider changing your storage plan.
Not Enough iCloud Storage	There is not enough space to save backups, photos, or other data.	Check iCloud storage usage and remove unnecessary data.

SIM and eSIM

Message / Symptom	Main Cause	Solution
No SIM	The iPhone may not be recognizing the SIM card.	Restart the iPhone and, if using a physical SIM, check whether the SIM card is installed correctly.
Invalid SIM	There may be a problem with the SIM contract status, the SIM itself, or its compatibility with the device.	Reinsert the SIM, and if the problem does not improve, contact your carrier.
SIM Failure	This may appear when the SIM card cannot be recognized properly.	Restart the iPhone and reinsert the SIM. If the problem continues, contact your carrier.
SIM Not Supported	The SIM may not be usable because of carrier restrictions, SIM locking, or other conditions.	Check compatibility between the device and the carrier.
Unable to Activate eSIM	There may be a problem with the network connection, contract information, or carrier settings.	Check the Wi-Fi connection, and if the problem does not improve, contact your carrier.
Unable to Add eSIM	Possible causes include problems with eSIM information, the contract, or device compatibility.	Check the information issued by your carrier and request a reissue if necessary.

Cellular and Phone Calls

Message / Symptom	Main Cause	Solution
No Service	Possible causes include being outside the coverage area, a network outage, or a SIM problem.	Move to another location, toggle Airplane Mode on and off, or restart the iPhone.
Searching	The iPhone is searching for an available cellular network.	Wait for a while. If the problem does not improve, restart the iPhone or check for carrier outages.
SOS / SOS Only	The iPhone cannot connect to your contracted cellular network, but emergency communication may still be available.	Check signal conditions and try moving to another location or restarting the iPhone.
Cellular Update Failed	There may be a software or hardware problem related to cellular communication.	Update iOS and restart the iPhone. If the issue does not improve, request an inspection.
Could Not Activate Cellular Data Network	There may be a problem with cellular settings, your contract, or signal conditions.	Check cellular settings and your contract status.
PDP Authentication Failure	There may be a problem with carrier network authentication or APN settings.	Restart the iPhone and check your carrier settings and outage information.
Call Failed	Possible causes include poor signal, a network outage, SIM problems, or contract status.	Check the signal conditions and try making the call again later.

Wi-Fi

Message / Symptom	Main Cause	Solution
Unable to Join the Network	There may be a problem with the Wi-Fi router, password, or wireless signal.	Turn Wi-Fi off and on again, and restart both the router and the iPhone.
Incorrect Password	The entered Wi-Fi password does not match the registered password.	Check the correct password and enter it again.
No Internet Connection	The iPhone is connected to Wi-Fi, but the router cannot connect to the internet.	Restart the router and check whether there is an internet service outage.
Weak Security	The Wi-Fi router is using an older encryption method.	Change the router’s security method to a newer one.
Privacy Warning	There may be a problem with the privacy settings of the Wi-Fi network.	Check the network settings and router settings.
This Network Is Blocking Encrypted DNS Traffic	The connected network is restricting encrypted DNS communication.	Use another Wi-Fi network or check with the router or network administrator.

Bluetooth

Message / Symptom	Main Cause	Solution
Cannot Connect to Bluetooth Accessory	There may be a problem with distance, battery level, or pairing information.	Turn Bluetooth off and on again, move the devices closer together, and pair them again.
Unable to Pair	The device may not be in pairing mode or may already be connected to another device.	Put the device into pairing mode, delete the existing pairing information, and reconnect it.

Face ID and Touch ID

Message / Symptom	Main Cause	Solution
Face ID Is Not Available	Possible causes include a problem with the TrueDepth camera or a temporary system issue.	Check the area around the camera and restart the iPhone. If the issue does not improve, set up Face ID again.
Unable to Set Up Face ID	The camera may not be recognizing your face correctly, or there may be a system problem.	Make sure the camera is not obstructed and set up Face ID again in a well-lit place.
A Problem Was Detected with the TrueDepth Camera	There may be a hardware problem with the TrueDepth camera.	If restarting or updating iOS does not resolve the problem, request an inspection.
Your Passcode Is Required to Enable Face ID	For security reasons, such as after restarting the iPhone, the passcode must be entered instead of using Face ID.	Enter the registered passcode.
Unable to Activate Touch ID	There may be a problem with the Touch ID sensor or the system.	Restart the iPhone and clean your finger and the sensor. If the issue does not improve, have the device inspected.
Unable to Set Up Touch ID	The fingerprint may not be read correctly.	Make sure your finger and the sensor are dry and register the fingerprint again.

Passcode and Security Lockout

Message / Symptom	Main Cause	Solution
iPhone Unavailable	This may appear after repeatedly entering an incorrect passcode.	Follow the waiting time displayed on the screen. If you have forgotten the passcode, the iPhone may need to be reset.
Security Lockout	The passcode has been entered incorrectly too many times.	Follow the instructions on the screen. If you cannot remember the passcode, the device may need to be erased and recovered.
Try Again in ○ Minutes	Passcode entry has been temporarily restricted because of repeated incorrect attempts.	Wait for the specified amount of time and then enter the correct passcode.

Apple Account

Message / Symptom	Main Cause	Solution
Cannot Sign In to Apple Account	There may be a problem with the password, network connection, or account status.	Check the network connection and password, and reset the password if necessary.
Update Apple Account Settings	Reauthentication is required after changing the password, updating iOS, or similar situations.	Open Settings and enter the Apple Account password.
Apple Account Verification	You need to sign in again for identity verification.	Enter the Apple Account password or other required information to authenticate.
Verification Failed	A network problem or an issue connecting to Apple’s services may be the cause.	Check the network connection and try again later.
Apple Account or Password Is Incorrect	The entered information does not match the registered account information.	Check the information entered and reset the password if you have forgotten it.
Apple Account Is Locked	The account has been restricted for security reasons or other reasons.	Use Apple’s account recovery process.

iPhone Activation

Message / Symptom	Main Cause	Solution
Unable to Activate iPhone	There may be a problem with the network connection, SIM, or Apple’s activation servers.	Check the Wi-Fi connection and SIM, then wait and try again.
Activation Server Is Unavailable	There may be a problem with Apple’s servers or the network connection.	Check the network connection and try again later.
Activation Failed	Verification of the network connection, SIM, device information, or other information has failed.	Restart the iPhone, check Wi-Fi and the SIM, and try again.
Activation Lock	Because a device with Find My enabled was erased, authentication with the previous owner’s Apple Account is required.	Sign in with the Apple Account registered to the device.
iPhone Locked to Owner	Activation Lock is enabled.	Authentication with the legitimate owner’s Apple Account is required.

iOS Updates

Message / Symptom	Main Cause	Solution
Unable to Check for Update	There may be a problem with the internet connection or Apple’s servers.	Check Wi-Fi, wait for a while, and check again.
Unable to Verify Update	A network or other problem has occurred while verifying the update file.	Check the internet connection and try again.
Unable to Install Update	Possible causes include insufficient storage, low battery, or network problems.	Check the available storage and charging status, then try again.
Software Update Failed	A problem occurred while downloading or installing the update.	Restart the iPhone and try again over Wi-Fi.
Unable to Prepare Update	There may be a problem with the update data or storage.	Check the available storage, delete the downloaded update, and download it again.

Recovery and Restore

Message / Symptom	Main Cause	Solution
There Is a Problem with the iPhone That Requires It to Be Updated or Restored	A system problem has occurred, such as iOS being unable to start normally.	Connect the iPhone to a Mac or Windows PC and try updating it first.
Recovery Mode	iOS cannot start normally.	Connect the iPhone to a computer and perform an update or restore.
iPhone Could Not Be Restored	Possible causes include the cable, USB connection, network connection, or system.	Check the computer and cable and try again.
Error 9	This may occur if the USB connection is interrupted during an update or restore.	Change the cable or USB port and try again.
Error 14	Possible causes include problems with restore data, the USB connection, or storage.	Check the cable and computer and perform the restore again.
Error 4013 / 4014	Possible causes include communication or hardware problems during an update or restore.	Change the computer, cable, or USB port and try again. If the problem does not improve, request an inspection.

Backup and iCloud

Message / Symptom	Main Cause	Solution
Unable to Back Up iPhone	Possible causes include insufficient iCloud storage or a network problem.	Check the available iCloud storage and Wi-Fi connection.
iCloud Backup Could Not Be Completed	The backup could not be completed because of insufficient storage, a network interruption, or another issue.	Connect to a stable Wi-Fi network and check the available iCloud storage.
This iPhone Has Not Been Backed Up	An iCloud backup has not been completed successfully for a certain period of time.	Connect the iPhone to Wi-Fi and power and perform a manual backup.
Unable to Restore from Backup	There may be a problem with the network connection, backup data, or iOS version.	Check Wi-Fi and the iOS version and try again.

App Store and Apps

Message / Symptom	Main Cause	Solution
Unable to Download App	There may be a problem with the network connection, storage, or Apple Account.	Check the network connection and available storage, then reopen the App Store.
Unable to Install App	Possible causes include insufficient storage, a network problem, or an unsupported OS version.	Check the available storage and iOS compatibility.
Unable to Update App	Possible causes include problems with the network connection, storage, or Apple Account.	Check Wi-Fi and available storage and try again.
Purchase Could Not Be Completed	There may be a problem with the payment method or Apple Account.	Check the payment method and account information.
Payment Method Declined	There may be a problem with the card information, spending limit, or billing information.	Check the payment information and register another payment method if necessary.
This App Is Currently Not Available in Your Country or Region	The app is not distributed in the country or region currently set for the App Store.	Check the App Store distribution region.
This App Is Not Compatible with Your Device	The iPhone model or iOS version does not meet the app’s requirements.	Check the supported devices and required iOS version.
Untrusted Developer / Unable to Verify Developer	The developer of an enterprise app or similar app cannot be properly verified.	Check where the app was obtained and do not use it if its safety cannot be confirmed.
Unable to Verify App Integrity	The iPhone cannot properly verify the app’s signature or distribution status.	Delete the app and reinstall it from an official distribution source.

Camera

Message / Symptom	Main Cause	Solution
Important Camera Message	A problem related to camera part verification or repair history has been detected.	Check the parts and repair history, and request an inspection if there is a problem with the camera.
Unable to Verify This iPhone Has a Genuine Apple Camera	The iPhone cannot properly verify the replaced camera part.	Check the repair history and consult the repair provider or Apple if necessary.
Unable to Use Camera	There may be a temporary problem with the app, camera function, or permissions.	Close and restart the app and check the camera permissions.

Safari and Websites

Message / Symptom	Main Cause	Solution
This Connection Is Not Private	There may be a problem with the website’s certificate or similar security information.	Do not enter important information, and check the URL and date and time settings.
Server Cannot Be Found	Possible causes include an incorrect URL, DNS problems, or a network failure.	Check the URL and internet connection.
Cannot Open Page	There may be a problem with the network connection, web server, or URL.	Reload the page and try another network.
Fraudulent Website Warning	The website has been detected as potentially dangerous, such as a phishing site.	Close the page and do not enter passwords or card information.

Mail

Message / Symptom	Main Cause	Solution
Cannot Get Mail	There may be a problem with the network connection, mail server, or account settings.	Check the network connection and mail account settings.
Connection to the Server Failed	The iPhone cannot communicate with the mail server.	Check the internet connection and mail server settings.
Cannot Send Mail	There may be a problem with the outgoing mail server settings, network connection, or authentication information.	Check the internet connection and outgoing mail server settings.
User Name or Password Is Incorrect	The login information for the mail account does not match.	Check the username and password for the email service.
Cannot Verify Server Identity	The certificate of the mail server or another server cannot be properly verified.	Check the date and time settings and server settings. If the connection seems suspicious, do not continue.

iMessage, SMS, and FaceTime

Message / Symptom	Main Cause	Solution
Not Delivered	The message could not be sent because of a network problem or the recipient’s receiving status.	Check the network connection and resend the message.
Unable to Send Message	There may be a problem with cellular service, iMessage, or SMS settings.	Check the network status and resend the message.
An Error Occurred During iMessage Activation	Authentication of the network connection, phone number, Apple Account, or other information has failed.	Check the network connection and date and time settings, then activate it again.
An Error Occurred During FaceTime Activation	There may be a problem with network or Apple Account authentication.	Check the internet connection and account information and try again.
FaceTime Is Not Available	Possible causes include the network connection, settings, or a service outage.	Check the FaceTime settings and network connection.

AirDrop and AirPlay

Message / Symptom	Main Cause	Solution
Unable to Send with AirDrop	Possible causes include Wi-Fi, Bluetooth, or receiving settings.	Check Wi-Fi, Bluetooth, and AirDrop receiving settings on both devices.
AirDrop Transfer Failed	There may be a problem with distance, network conditions, or storage capacity.	Move the devices closer together, check the network conditions, and send the item again.
Unable to Connect to AirPlay	There is a problem connecting to the network or AirPlay-compatible device.	Connect both devices to the same Wi-Fi network and restart them.

Apple Pay and Wallet

Message / Symptom	Main Cause	Solution
Unable to Set Up Apple Pay	Possible causes include Apple Account, region, device settings, or card issuer requirements.	Check the region settings and Apple Account, and also check with the card issuer.
This Card Cannot Be Used	The card may not support Apple Pay or may be restricted by the card issuer.	Check compatibility with the card issuer.
Could Not Add Card	There may be a problem with the card information, authentication, or network connection.	Check the information entered, and if the problem does not improve, contact the card issuer.
Apple Pay Is Not Available	There may be a problem with the device settings, card, or system.	Restart the iPhone and check the card status. If the issue does not improve, consult Apple or the card issuer.

AirTag and Find My

Message / Symptom	Main Cause	Solution
AirTag Found Moving With You	An AirTag that is not registered to your Apple Account has been moving with you for a certain period of time.	Open the notification and check the AirTag’s location and information. If you do not recognize it, prioritize your safety when responding.
Unknown Accessory Detected	A Find My-compatible device with an unknown owner may be moving with you.	Follow the notification instructions to check the accessory.
No Location Found	The target device may be offline, powered off, or outside communication range.	Refer to its last known location and wait for the device to come online.
Unable to Connect to AirTag	Possible causes include Bluetooth, distance, or the AirTag battery.	Move closer to the AirTag and check Bluetooth and the battery condition.

VPN and Certificates

Message / Symptom	Main Cause	Solution
Certificate Is Not Trusted	The iPhone cannot trust the certificate used by the website or network.	Stop suspicious connections and check with the certificate or network administrator.
Unable to Connect to VPN	There is a problem with the network, VPN server, user information, settings, or other configuration.	Check the internet connection and VPN settings.
VPN Connection Was Disconnected	A network disconnection or problem with the VPN server may be the cause.	Check the network status and reconnect to the VPN.

Personal Hotspot and CarPlay

Message / Symptom	Main Cause	Solution
Unable to Start Personal Hotspot	There may be a problem with your mobile plan, cellular service, or settings.	Check cellular service and your contract details, then restart the iPhone.
Unable to Connect to Personal Hotspot	There may be a problem with the Wi-Fi password or network conditions.	Check the password and restart both devices.
Unable to Connect to CarPlay	Possible causes include the USB cable, Bluetooth, Wi-Fi, or vehicle settings.	Check the cable or wireless connection and restart the iPhone and vehicle system.
CarPlay Is Not Available	Possible causes include CarPlay settings or restrictions imposed by Screen Time.	Check CarPlay and content restrictions in Settings.

Parts and Repair Warnings

Message / Symptom	Main Cause	Solution
Unknown Part	This may appear when the iPhone cannot properly verify a replaced part.	Check Parts and Service History in Settings and consult the repair provider if necessary.
Important Display Message	There may be a problem verifying a replaced display.	If there are problems with the display or touch operation, request an inspection.
Important Battery Message	A problem related to battery verification or replacement history has been detected.	Check the battery condition and repair history.
Important Camera Message	A problem related to camera part verification or replacement history has been detected.	If there is a problem with the camera, consult Apple or the repair provider.

Passwords and Security

Message / Symptom	Main Cause	Solution
Password May Have Been Compromised	A saved password may be included in known leaked data.	Change the password for the affected service immediately.
Security Recommendations	A weak password, reused password, possible data leak, or similar issue has been detected.	Check the affected password and change it.
Password at Risk of Being Compromised	The password currently in use may not be secure.	Change it to a strong password that is different from those used for other services.

Basic Troubleshooting Steps to Try First

When to Consider Repair or Support

If the same warning repeatedly appears even after restarting the iPhone or checking the settings,
or if a message indicating a hardware problem involving Face ID, the camera, battery,
cellular communication, or another component does not disappear,
consider contacting Apple Support or an authorized service provider.

In addition, if there is a physical abnormality such as excessive device heat,
a swollen battery, or failure to operate normally after being submerged in water,
it is safer not to continue using the device forcibly.