Galaxy Tab S no longer recognizes decrypt password shortly after Lollipop update

[ColorConfinement]

I have a Galaxy Tab S 10.5 which I encrypted a while back just to try it. I had no problems at all with it until recently, shortly (but not immediately) after the Lollipop update. After the update the tablet unlocked properly with my password. I then changed it so that after the pre-boot authentication it would use finger print for screen unlock. Everything seemed fine at this point. I then set the tablet down on the table attached to a charger for several hours. Eventually I heard the boot up jingle the tablet makes when it restarts, but I had not touched the tablet at all for hours before I heard this. I went over to check it out and saw the pre-boot authentication screen so I typed in my password, but it said "Try again". I tried several more times and tried power cycling the tablet. Occasionally I would get a 30 second cool down timer. Finally, I got this message:

An incorrect attempt to unlock the device has been made. You have 9 attempts left before your device is reset to its factory settings and all data, including files and downloaded applications, is erased from your device storage.

I am now down to five tries with no luck. I am basically 100% positive I am using the right password and that I entered correctly. I don't have anything truly precious or irreplaceable on the tablet so it won't be a tragedy if I have to reset it, but I have a few files, screen shots, and pictures that I would like to get back if possible. If anyone knows what might be causing this, or of an alternative way to access the data (which I do have the password for) I would be grateful to hear it. Otherwise, let this be a warning to back things up regularly.

 

[scattersnap]

I have the exact same issue with a Galaxy S4 (i9505, running 5.0.1) since yesterday evening. I had to change the password due to an Airwatch MDM requirement.

Afterwards a Playstore Google internal update was completed (around 30 MB, I don't remember the exact name). For some reason the lock screen became a bit weird afterwards (letters were party only shown as boxes).

That's why I rebooted and now I'm not able to either log in with the old or the new password to get past the decryption screen. I'm also down to 6 remaining tries now.
Nothing extremely crucial on the phone but I would like to avoid the pain of setting everything up again (even with a backup it takes quite same time).

Does anybody else have a similiar problem? This might be a bigger Lollipop/Samsung bug.

 

[ColorConfinement]

Thanks for contributing. I'm sad it happened to you but at least now I know I didn't just somehow forget my password One similarity that sticks out to me is that not only did we update, we also changed some aspect of our passwords. Anyone reading this should be cautious if they are going to do the same on a Samsung device with Lollipop.

Which reminds me: I'm new around here so I don't know if this is possible, but can this also get listed in the general Lollipop thread and/or general Samsung thread? As scattersnap pointed out, now that something similar has been reported on two different devices I'm thinking this may be a larger problem than just the Galaxy S4 or Galaxy Tab S.

 

[WillyBean12]

I am experiencing the same issue. My tab was encrypted before the lollipop upgrade. After the upgrade, I change the security setting to fingerprint. Then when I restarted, my old password is no longer recognized. Any ideas on how to fix this?

 

[ColorConfinement]

WillyBean12 that is exactly what I did, which means this is probably reproducible. If I end up giving up and resetting my Tab I will see if I can make it happen again. It is possible this is some corner case which stops occurring if you wipe after the update, which would make it hard to reproduce. We should look into contacting Samsung, or if there are any other forums for Android stuff we should post there. If I have to reset my tab I'll see if I can make this happen again.