This is not an acceptable solution for all taxpayers. If Form 2555 is included with the return, even if claiming zero FEIE after an adjustment, then Schedule 8812 Additional Child Tax Credit and retirement account contributions will not be permitted, with the added problem that manual overrides of ACTC on 8812 are also not permitted with an e-filed return. Not everyone wishes to or is permitted to use form 2555, such as in cases when the election has been revoked.

With Lacerte 2020 41.0428 it does not appear that a missing FEIN causes a diagnostic failure. I'll soon see how the Service replies when I e-file the next return.