Songs from the library can't be deleted?

If I go to "delete", with a song always comes "error when deleting 1 song".

What should I do to make it work again?

Everything went before that, did not stop or anything.

Have a Huawei p9 Lite… If that helps

I do not know, but the PC is there by mouse click "Properties" and there you can set the, whether it is erasable

Hm ok, that's unfortunately not on my phone.