When I was doing research online I saw a similar post with the same error message as yours, that post is in a resolved state and with the following workaround, although it is not applicable to the error we have in this thread here but maybe worthwhile for you to take a look. I copied here for your reference. Good luck.
Solution: view your form 1116 for year 2020 in form view mode and override manually value "various" to date 12/31/2020. This is a date field and should contain date value. Last year this field was populated by turbox correctly.
