Admin/Setting/GeneralCommon - Logo - Remove picture - not working

nopCommerce version 3.9

I modified the logo of my store in Admin / Setting / GeneralCommon once.
But now I can not modify it, the "Remove picture" button does not work.
If it is not a bug, how can I change the logo from nopComerce - Admin.

It works fine. Do you click "Save" button after "Remove picture" one?

Thanks for your time.
The problem has already been solved.
I was working in relese mode and only the "Remove picture" button appeared, it did not work and the "Upload a file" button did not appear.
I needed to go to debug mode to do other tests and I was surprised that the "Upload a file" had appeared and everything worked perfectly since then.

Thanks...