I can enter it, but it remains in an error mode. Meaning, if you run error check again, it wants you to remove the very information you just put in, saying there is already a SSN present!
The only way to fix this problem is to enter my SSN in an EIN format, in the signing block. (The other way to fix it, is to leave the partners names with the words "Revocable Trust", but then change the type to "Individual". That, of course, is both a kluge and factually incorrect.)
