This might be one where you just have to suppress error checking.  E-file>Efile support tools>Disable efile error...

It'll suppress critical diagnostics for that return only for right then only.  Efile the return and you're done.

There are a few ghost diagnostics like this in Lacerte.  Once you're certain that the forms are right, go for it.  Maybe search on here first, because usually other users have posted about it.