I had that happen to me the other day and I just closed pathfinder and reopened it and it logged me. No clue why I had been using it for some time and now I am not logged in. I figured it was something at their end since it logged me back in when I restarted the app.
I also got a popup on Thursday that said Pathfinder has stopped working and windows closed it. I reopened it and kept going.
73, Bob KB4CL
From: dxlab@... [mailto:dxlab@...]
Sent: Saturday, March 05, 2016 7:01 AM
To: dxlab@...
Subject: [dxlab] Not logged in to QRZ
Getting up pop up indicating not logged into QRZ. I'm setup for auto login via pathfinder. If I open pathfinder and login manually it all works. I've checked my login and password in pathfinder config and its all good.
Only upgrade I did was to DXView recently. All modules are up to date. Any ideas.
Bob, N2NF