When just launching Toad, an error is given,
"An invalid character was found in text content.
.
Line:_2
<FilterHistory><Filter Type="15">ps?IAS?."
This was only and issue after trying to search for objects based on a filter set with an unexpected character. The window was closed and the search did not complete, but the error now always occurs. After clicking OK to the error, nothing happens and Toad does not open.
Filter history stores the search value and is affecting launch.
Go to C:\Documents and Settings\<personal folder>\Application Data\Quest Software\Toad for Oracle\<version>\User Files and find and rename the SBFilterHist.xml file.
Launch Toad
If issue persists, upgrade to latest version of Toad at https://support.quest.com