Windows 10: Can't change background lockscreen on Windows 10

My lockscreen became grey, someone can help me with this problem?

:)

 

About changing current lockscreen background

There is a problem in my windows 10 pro , Once i change my lockscreen background ,i can't change it . I have try atlesat 100 time's but windows say that it can't change the current lockscreen background.Anyone can give me a solution
to this problem

 

Change Background Image Lockscreen

Dear,

Since today I cannot change the background image of my lockscreen on my Nokia Lumia 520.
Normally when you tap change photo you can scroll through pictures and select one by tapping to crop it the way you want to use as your background image on your lockscreen. But now when I tap "change picture" I can scroll through my background images but
when I try to select one by tapping it, it just takes me back to the settings without giving me the option to crop the image and without changing my lockscreen background image... I know how to do it because it used to work, but now it odesn't anymore. I've
been trying to change it for a whole day and I've restarted my Windows 8 Phone several times during this process... Any ideas? It's rather unpleasant... Thanks in advance.

 

Lockscreen Background Won't Change

This was the second problem occurred after updating my windows 10 to version 1607 (OS build 14393.0)

1st was the keyboard won't work thing on start menu search bar and MS apps.

And now I noted that, the lockscreen background doesn't change, I tried several number of pics. But i got nothing.

No error messages or anything...

just the loading circle keeps spinning... thats all. Background won't change.

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Need help✌