The workaround that worked for me and allowed me to file my return digitally, was to delete the Tax Work Sheet form entirely (after printing it out to preserve the information).
I think the issue might have to do with having initially (months ago) marked the choice of whether to file with a standard deduction or itemized deductions, as "standard deduction", but marking it, or something related to it, as "estimated" so the program would alert me and I would know to review the decision. I subsequently determined that this year it was better to file with itemized deductions in response to a prompt, but I don't recall removing a "marked as estimated" flag when that decision was made. This idea is reinforced by the names "STDref" and ITEMref, which could easily refer to something to do with Standard and Itemized deductions.
