In Toad 10.6.0 and Toad 10.6.1.3, when you send the CodeXpert results for a "package" to the Editor, Toad spawns two Editors instead of one Editor and two tabs (as in Toad 10.5). Hence Toad always throws the error:
WORKAROUND:
Downgrade Toad to version 10.5.1.
STATUS:
This issue has been identified as a defect in Toad for Oracle 10.6.1 and is waiting for fix in a future release of Toad for Oracle.