Hello @LeizylM,  As I mentioned on my 1st post, "A verify & rebuild finds no errors, nor does the File Doctor."

I mentioned the link you provided in my 1st post as well. None of these resolved the issue. Solution 3 / the Excel Method does not work.  The IIF import results in an error indicating QB ONLINE "It's a list or transaction that is not supported by the IIF import process."

Please let me know what else I can try.