Reset your Toad user files to clear temp / cache / corrupt files.
How to Reset Toad for SQL Server (TSS):
NOTE: Please try not to leave TSS running overnight or force close TSS as these can cause user files corruption.
NOTE: Replace the "X.X" below with your TSS version number.
1) Fully exit Toad for SQL Server (TSS).
2) Go to: C:\Users\<YOUR_USER>\AppData\Roaming\Quest Software\
3) Rename the “Toad for SQL Server X.X” folder to “Toad for SQL Server X.X OLD”.
4) Start TSS (this will cause TSS to create a new “Toad for SQL Server X.X” folder).
5) When asked if you want to ‘migrate’ settings from previous versions, choose NO or CANCEL.
6) Re-test the issue.
NOTE: If you would like to transfer back your Saved Connections, see the steps below.
1) Fully exit Toad for SQL Server (TSS) again.
2) Go to the OLD “Toad for SQL Server X.X OLD” folder you renamed in Step 3 above.
3) Perform a Copy on the “Connections.xml” file (make a backup of this file just in case of errors).
4) Go to the NEW “Toad for SQL Server X.X” folder that was just created by TSS.
5) Paste the “Connections.xml” file in there.
6) Start TSS and you should now have your previous Saved Connections in the log-in screen.