OK, open the terminal (it is the >- symbol on the Toolbar). type the following
ls -al /mnt/user0
That will get you something like this:
total 4
drwxrwxrwx 1 nobody users 75 Sep 8 02:30 ./
drwxr-xr-x 9 root root 180 Aug 6 10:58 ../
drwxrwxrwx 1 nobody users 305 Sep 1 18:20 Backup/
drwxrwxrwx 1 nobody users 273 Nov 6 2017 CommunityApplicationsAppdataBackup/
drwxrwxrwx 1 nobody users 4096 Aug 27 19:01 Media/
These are the Shares on this server. Now pick one of the shares that contains a file that has the problem. I am going to proceed using the Share 'Media'. (Note capitalization is IMPORTANT with Linux!!!)
ls -al /mnt/user0/Media
This gives an output like so:
total 8462508
drwxrwxrwx 1 nobody users 4096 Aug 27 19:01 ./
drwxrwxrwx 1 nobody users 75 Sep 8 02:30 ../
-rw-rw-rw- 1 nobody users 7726504 May 24 2017 100-Magic_Act.mp4
-rw-rw-rw- 1 nobody users 169788268 Mar 2 2013 107D_OutdoorCupboard.mp4
You will, of course, have will to pick a path down to a directory which has a file with the permission problem. When you find one, left click at the beginning of it and 'sweep' the entire line. Now right click on it and copy it. Paste into a reply. Be sure to format it as 'Code' --- the </> symbol on the Toolbar --- as this will keeping everything lined up neatly.