Hi annonnyma and welcome to our community
We have never been able to have multiple users simultaneously
accessing the same project by simply placing it on a server. The
way it works with a source control system is by having it stored
centrally on the server. Then the source control system handles
checking in and checking out by maintaining a "Working folder" on
your LOCAL hard drive. The end result is that each help author
actually has a full copy of the help system source files on the
server. As they work on different bits, they are actually working
locally off their C drive. At no point do you ever directly access
and edit the files on the server. The source control system handles
copying them back and forth.
RoboHelp Server should not be needed for source control if
you are using VSS.
So copy the project locally, then possibly rebuild the .CPD
and you should be good to go.
Cheers... Rick