Hi Maxim

I think it is a permissions related problem - our files are not permission related, I should be able to read all, in fact I'm the only one that backs them up, never had this problem when we used PC

But can you explain what do you mean by "I can't READ ... dog"? - sorry spellcheck change from dwg to dog and i missed it

Can you open these DWG on PC side? - I can only see any files created on PC but can see at any files created by MAC 

Which error message do you get? Do you open drawings on PC directly from the server? - ok no error message at all, I can open the older files that was created by PC on the PC and MAC

If yes, than what if you copy DWG files to PC local drive at first? - Cant even see the files created by MAC on the server or backup HD to open then with PC, 

The files created by MAC I can't see on the Backup HD BUT can see and open on the server, it seem there is something on the system that stops the new MAC created files being copied over to another HD ? is that possible but should not have been set up for that!

I hope this iinfomation  helps, and thank you for your help 

Barry