An individual tax return for a couple filing jointly may reject with code IND-018-02 if the primary taxpayer is the decedent:
Reject Code: IND-018-02
If 'PrimaryDeathDt' has a value in the return, then 'InCareOfNm' in the Filer address in the Return Header must have a value.
In a MFJ return with one spouse deceased, the living spouse should be the primary taxpayer. This is an IRS limitation.
To fix this reject, swap the relationships between the taxpayer and spouse, ensuring the living spouse is the primary taxpayer. Be sure to swap the SSN, name, and birthdate. After making this change, examine the return for accuracy, and check state returns as well. Finally, when you're finished you can e-file it.