Hi @maxim_k 

Yes,  the files are on a network drive, well we call it a server.  The server is a separate iMac that sits a few metres from my desk and we connect to it over Wi-Fi.  There are 2 of us here working off that iMac server.  

I could copy the files to my desktop and see if that helps, but in the long term I'll need to fix the main issue.

I will try and reset Autocad like you suggested

Thank you

Amanda