You have most likely opened a different catalog file.
Go to File->Open Recent and select each catalog listed there.
Did you - by mistake - open some backup instead of the most current catalog?
Search your drives for catalogs (lrcat), open and check which one is the most current.
It seems that you have opened a different catalog.
Check the name of catalog and also try File -> Open recent
Jive that was the problem and I have been able to get back to my files.
Thank you for the help!
You are Welcome Herman