First solutions:
After the error message the Encryption Unsuccessful appear, choose ‘Reset Phone’ at the bottom of the message, and your phone will reboot automatically and booting to recovery mode, and wipe the data cache. Just wait the process until complete.
After done with wiping data and cache, the phone will reboot automatically. For the first booting, it take time for two to three minute. So, you must to wait quite longer.
Second solutions:
If the issues are still persist, remove the SD
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