Device Unlock App - Error Messages

When you launch the Device Unlock App on your phone, a series of messages may appear but only one is valid for unlocking your phone successfully. 

Follow these steps:

1. Connect your phone to a WiFi network.
2. Launch the Device Unlock application and select the Permanent Unlock option. Learn more about it here.

If you see the message below you can unlock your phone using our Device Unlock App Service.

"Unlock Failed: This mobile wireless device is not eligible for unlock. For Device Unlock eligibility details, please go online or contact Customer Care."

If you get any other message, search for the error message in the table below and follow the recommended steps to resolve the issue:


Error Message What to do
Unlock Failed : System maintenance error, try again later.
  • System Maintenance is currently underway.
  • Wait and try again later.
Server not responding. Please try again later.
  • No response is received from the server.
  • Try using a different internet connection.
Unable to connect to the server at this time. Please try back again later.
  • Update the app using the Play Store.
  • Attempt the unlock using the mobile network.
Failure in applying the unlock settings. Please try again.
  • The device must be connected to the mobile network (including domestic and international roaming).
  • Disconnect from WiFi and try again.
Failure in processing the request. Please reboot the device and try again.
  • Ensure that your device has sufficient memory
  • Restart the device and try again
No internet connection available. Please try again when an Internet connection is available.
  • No internet connection is available.
  • The device is not connected to 3G/4G LTE.
  • A non-compatible SIM card is being used.
Data corrupted during transfer. Please try again. Error during data transfer. Please try again.
  • Ensure the device has a stable mobile signal.
  • Restart the device and try again.
Unlock Failed: Unlock Approved: Mobile Device is permanently unlocked
  • Solution 1: Perform a hard rest and attempt a second unlock.
  • Solution 2: Perform two consecutive hard rests without attempting the unlock and once the second hard reset has been performed attempt the unlock again.
  • Make sure the phone has the latest Android version available for that device.
Device not recognized by your service provider. Please call customer care.
  • Rooting your device will disable the unlock application.
  • Download the latest T-Mobile/MetroPCS software to continue.


* doctorSIM will not be held liable for any damages to the phone due to rooting or performing a hard reset (factory reset).

If the error persists, please contact us for assistance.




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