1. Close Toad
2. Go to C:\Users\username\AppData\Roaming\Quest Software
3. Rename folder 'Toad for SQL Server X.x' to '...X.x_old'
4. Launch Toad. Do not migrate settings, if prompted
5. Close Toad again
6. Go back to C:\Users\username\AppData\Roaming\Quest Software\Toad for SQL Server X.x_old
7. Copy Connections.xml to the newly created Toad for SQL Server X.x folder.
8. Relaunch Toad and retest your issue