[v48] - move/copy to hidden folder does not work

[masterjp]

I wanted to copy or move picture files (*.jpg) from device memory (documents folder) to the hidden picture\.thumbnails folder.
I actived the show hidden files folder switch in settings menu. I can see the folder in device memory view,
but the move or copy dialog do not let me choose the hidden folder for destination folder.

[B.Douille]

I don't know what prevents such action but anyway I don't think this is a good idea to move, save pictures or modify existing thumbnail in this folder.
There are many .Thumbnails folder in the structure and it’s all for system/app usage. Touching them leads to unpredictable results.