Try clicking on the Detail button, it should give you more details on the problem and it’s cause.
There is a troubleshooting page for version control in the Mendix documentation, so I would also suggest taking a look at this once you have some more details and see if the issue is listed there.
If that fails, send a copy of the log (Goto Help → Open Log File Directory) to Mendix support.
https://docs.mendix.com/refguide/troubleshoot-version-control-issues/
Good luck!