The copy on the send/receive server was incomplete - probably the initial send/receive for the project failed.
I have removed the project, so the next send/receive should work.
If the folder for a project was copied from one computer to another, it’s possible that there is a lock file in repository that will need to be removed manually.
You can also get a message about locked files if your anti-virus program is locking files during send/receive. I’ve asked some people to exclude the C:\My Paratext 8 Projects folder from the scan list to avoid this problem.
If you continue to have problems, it’s best to use Help > Report a Problem since that includes a log that helps us see what is going wrong.