I have set a password from android device manager but it is too long to type from the phone - i cant change the password from the device manager. What do i do?
I think I just had the same problem. It took me awhile to figure out. Super frustrating.
If your problem is you can unlock your phone but cannot update the password, then try truncating the password to 16 characters. The lock screen will only except 16 and will ignore everything after the 16th. However the password entry field in the settings will except much more. This is why you can log in, but cannot update the password.
So if your password is: 'qwertyuiopasdfghjklzxc', then just type: 'qwertyuiopasdfgh'
hope that solves your problem.