User unable to connect, gets error messages, "PL/SQL Parser not found," "missing Toad User Tables," and access violations.
Issue began after making changes to mapping the Proc Templates to a mapped network drive in the Toad | Options | Proc Templates. Taking the computer home, the network drives became unmapped. Since then the issue has remained even after reinstall.
Reset setting and preferences:
1. Shut down Toad for Oracle.
2. Browse to C:\Program Files\Quest Software\Toad for Oracle\User Files.
3. Locate the file Toad.ini. Rename it to Toad.old.
4. Launch Toad and retest the issue.
Completely uninstall/reinstall Toad.
See solution #12846 Toad Installation - How to completely uninstall and reinstall Toad for Oracle.