Are you using ICS and pulled your phone out of your pocket only to find that it had this screen, saying "Encryption unsuccessful" and your only option a button that said "Reset Phone"?
Don't press it! Try rebooting a few times with your external sdcard out first. Sometimes that works. If not, this may work:
Originally Posted by jmtheiss
got the dreaded encryption screen. Following the instructions here, I pulled my external SD, didn't hit the "reset device" button, but instead rebooted a few times. It wouldn't change, so I rebooted to download mode and flashed a KH3 Heimdall one-click that I had. It flashed fine, booted up, but the My Files application said I didn't have a card inserted.
However, when I connected it to my computer, my computer recognized the Internal SD. I'm now backing up all my stuff to a safe place. Not really sure where to go from here, but at least I've got my stuff backed up.
UPDATE: Unplugged USB cable, Media scanner ran, files now showing up on phone!
If that doesn't work or you have already hit reset, follow the guide below to get your phone usable again:
# internal sdcard that is no longer working dev_mount emmc /mnt/emmc 1 /devices/platform/s3c-sdhci.0/mmc_host/mmc0 # external sdcard dev_mount sdcard /mnt/sdcard auto /devices/platform/s3c-sdhci.2/mmc_host/mmc2