Sounds like a Permissions issue.
...maybe Firewall?
it could be server setting issue? ask your IT Manager. or try to reboot your server. thanks
someone might have copy / pasted local file on the server..
so when you open it.. its struggling to find the central file.. which is actually might be missing..
and you will get this error
you may save it " as a central file " in save option..
and then recreate local and continue working...
further you can even check " history " of that file to check who worked on it..
using
select " show history" and then select the " revit file " it will give all the logs of saved, username, date...