Lock screen problem for Sony M5

[Xylophone]

After upgrading to marshmallow, I cannot change the type of screen lock for my Sony M5 , is there any solution without clearing the credentials ?

[Whatafack]

I was drunk and forget my pass , can i do , dont wanna throw it

[Chini29]

My Sony Xperia M5 Dual lockscreen is not working. When I have tried to make it on, it is showing that System is stop working and retrive from there. Please suggest some needful.