Our Perforce server changed IP address overnight, so I had to update it in P4V and command line.
However when I try to start up P4V, I get a popup which says: "Workspace "sys_local" does not exist". If I click OK, P4V just crashes. I uninstalled, downloaded the latest version, reinstalled, but still the same problem. It was working fine yesterday, but this morning when I updated to the new server IP, I get the popup. The command line still works fine.
I created a new workspace called Sys_local from the command line. That enabled P4V to start up, albeit in an empty workspace. Then I just set up a new connection to my previous workspace, and it seems to be working.