I had no luck fixing the date. I had 3 1099-DIV entries with foreign taxes, and it put the numbers ONLY in column C, even when I had all of them as 'various'. I was getting the reject - missing country code.
But, it was putting 1099 taxes in the date field in Section II, so I expect that was the real error. Everything was correct on the 1116 worksheet. When I did an override of the date on form 1116, it complained, and also stopped me when I did error checking.
If the amount of the tax is 'reasonable' (your definition 🙂 ) switch from a credit to a deduction. It won't take as much off the taxes, but at least you will be able to file. Then file an amended if/when Turbo Tax gets it fixed.