Unable to disable password on Android screen lock I would like to disable the PIN/Password of my Android screen lock but I am unable to  do that as the relevant option is greyed out. Please see screenshot:

(Click image to enlarge)
Please read the subtitle of every remaining button...

"Because you've turned on an accessibility service, your device won't use your screen lock to enhance data encryption."

You need to turn off accessibility services before you can change any settings here.

Settings-> System section-> Accessibility-> 
Turn off each process using the accessability services until you are allowed to change your password again.

A second cause may be what Journeyman said, but you seem to be running an older android version that doesn't support that.