My w-2 from a Delaware Company has a blank spot for Employer's State ID. Is this an error?

[ThomasM125]

I'm not sure if that is an error, but according to this from Deleware.gov, an employer's Delaware ID number is it's 9-digit Federal employer ID, which you will see in box b on the W-2 form:

I suggest leaving the entry blank, but if that causes problems you can try entering the federal ID number.