Currently when I use the client to load a project from the server I am able to view the names of the diagrams created by other users but if I attempt to load one of these diagrams I receive a "A problem has been encountered on the server" error.
You likely have a filesystem permissions issue - when someone else creates a file then you might not have access to open the file for update. You can normally manage this by using techniques such as group level permissions . I suggest that you should contact tech support for help with your setup.
I don't think it is the file permission issue in this case. The files belong to a group that all of the users are a part of and the everything in Workspace has been set to group readable and writable all the way down.
We've even experimented with making a project universally readable/writable.