Single Record Viewer disappears when double clicking on "Next Record" icon in the Schema browser and I can't bring it up again for the
Go to the View | Toad Options | Schema Browser | Data Tab and uncheck the second checkbox "Set focus to grid after selecting table,
view, or materialized view". (If it is already unchecked, then check it - Apply, then uncheck)
Waiting for fix in future release of Toad for Oracle.
An Access Violation error may occur instead of the single record viewer just disappearing.