Don't panic - this is fixable and has something to do with the new installer.
As written in the upgrade dialog window - please completely uninstall the previous tigerVPN app first.
If you hit "update" the Windows installer is just installing the 3.0 version of tigerVPN without first removing 2.0. This creates login issues because our service works with login tokens.
Locate tigerVPN in the software settings and un-install the old version.
To be safe, uninstall all tigerVPN related components (if you installed the new version already)