My client is filing MFS. I've filled in the form allocating income between spouses showing that all of income goes to the tax payer and 0 to the spouse (which, by the way, was annoying that I have to fill that out manually since I selected for every single one of those items whether they belonged to the tax payer or the spouse).

In the critical diagnostics it still says "This federal return should not be filed with the IRS. It is only generated for the purposes of computing the California Registered Domestic Partner state return."

Why does it say that? This tax payer definitely needs to file a federal return. (The spouse doesn't, but this federal return is for the tax payer who earned all of the income, not the spouse.)