A married person can not be claimed as a dependent on any tax return. If you are filing a joint return with your husband, then you are both the "tax filers". If you have no children or other qualifying dependents, then you two have no dependents at all.
In effect, when filing as married, filing jointly, both spouses are automatically included in both the standard deduction and the tax rate tables. One selecting the other as a dependent is unnecessary, and doing so would effectively be claiming them twice.
I think the 2 answers are missing the point. The user is filing Joint. But the program is saying the husband is not eligible to be a dependent which of course they know. Why is the program saying that? I think this goes along with the other posts about an error of the spouse being a dependent. @Carl can you ask in the Lounge?