Using 11.1.27.0.
I have two insurance payment checks. They don't appear on the create deposit screen, and when I try to delete them it states "Not allowed to delete a payment attached to a deposit." But they're not attached to any existing deposits, either. The insurance check info screen doesn't state anymore which deposit it's attached to, which is too bad, because it might have provided some info about what happened.
UPDATE:
User error. (If anyone's interested, they were attached to the 'online payments' deposit which I was closing out the year with.)
NEVERMIND.