"ORA-01406" fetched column value was truncated error message received upon viewing data in Editor and Schema Browser.
NLS_LANG of Oracle home directory is set to UTF8.
Select Session | New Connection and select Oracle Home Editor icon ('...' icon under Installed Clients). Double click on the NLS_LANG entry and edit it to AMERICAN_AMERICA.WE8MSWIN1252. Hit OK, close Toad and re-launch it.
1. Go into the Registry by clicking on Start | Run | "regedit".
2. Browse to HKEY_LOCAL_MACHINE | Software | Oracle
3. On the right hand side you may see NLS_LANG for your default home. Double click on it to modify it as necessary.
4. Inside the Oracle folder, you may find other folders for your Oracle homes, such as ID0 and HOME0 for your first Oracle home, ID1 and HOME1 for your second home. And so on.
5. If necessary replace their NLS_LANG parameters as well.
6. Restart Toad and Toad should pick up the new NLS_LANG.
Disclaimer : Quest does not provide support for problems that arise from improper modification of the registry. The Windows registry contains information critical to your computer and applications. Make sure you back up the registry before modifying it. For more information on the Windows Registry Editor and how to back up and restore it, refer to Microsoft Article ID 256986 "Description of the Microsoft Windows registry": http://support.microsoft.com/default.aspx?kbid=256986