It has been a while, but this is a message related to Access
Replication. Is that what you are using? Replication is (next to
workgroup security) one of the most advanced topics of Access
programming and should never be used unless you REALLY know what you
are doing.
Assuming this is the Design Master that is now messed up, you should
read up on the topic of Recover Design Master.  I seem to remember you
can create a new database, import all objects, and use the Recover
Design Master procedure to get back on track.
David Fenton frequents this and other Access news groups. He knows
quite a bit about this subject, should you need professional help.

-Tom.

If it's not the Design Master, you won't be able to make changes.

The part about "maximum number of replicas" is problematic -- I
don't recognize that as a common error, since the maximum number is
actually 65K replicas. It might be that the retention period has
expired (the default is 1000 days), which would mean the replica is
no longer usable (i.e., can't be synched, though it can still be
edited).