It looks like owners of the Samsung Galaxy S6, Galaxy S7, Galaxy Note 4 and Galaxy Note 5 running on Marshmallow should steer clear of passwords and fingerprint security for now, as the Android update is locking some users out of their smartphones.
Reddit user McNooberson brought the news to light in a thread on the /r/android sub, explaining the issue.
"[Other owners] all used fingerprints to unlock their screen and it stopped recognizing their fingerprints and even trying. Backup password doesn't work and Google sign in doesn't either," he says.
Based on the reports, the lock issue doesn't affect every unit, but enough users have come across it to bring attention to the problem on the interweb.
In the case of Galaxy S6, Galaxy Note 4 and Galaxy Note 5 owners, all they need to do to avoid it is to hold off from updating Android. On the other hand, Galaxy S7 users aren't so lucky, as the handset runs on Marshmallow out of the box.
Fortunately, there are some workarounds and possible fixes to address the lock issue.
First off, for those who want to update their Galaxy S6, Galaxy Note 4 or Galaxy Note 5 and prevent the problem from occurring, just turn off the password and fingerprint authentication before upgrading to Marshmallow.
Next, for those who already updated or those who are on the Galaxy S7 and got locked out, just head on over to the Samsung Find My Mobile website. There, simply lock and unlock the handset. However, a Samsung account connected to the device is a requirement for this method to work.
Needless to say, anyone who can't access their Galaxy device and doesn't have a Samsung account linked to it will have to talk things through with the smartphone maker's customer support.
As for the cause itself, it's reportedly on account of a problem with encryption that messes up the passwords and fingerprints stored in the device.
It's worth mentioning that there are also reports of other Android smartphones facing similar issues. In other words, Marshmallow plus any form of login is a terrible combination for now.
Hit us up in the comments section below if you're one of the unlucky Galaxy owners who got locked out of their device.