Hi cscooper,
When GUI client or Tray Notifier is executed, it tries to load the existing configuration. It looks like something goes wrong during this process.
Find the <.smartbear> folder under your Windows account's folder in the "C:\Users" directory, rename it to <.smartbear-copy>, and try to run the GUI client using the administrator privileges (right-click it and select run as "administrator").
If the issue still persists check whether the command-line client fails too:
1. Open your command prompt.
2. Change the directory to the one where the Collaborator client is installed and execute the "collab login" command.
If it fails, share the output.
