Yes have confirmed other elements are not at issue.
I import these files every single week, same errors... until today.
I would add that all of these files import individually just fine... it's just when I try to do more than one at a time it crops up.
For example, I have three similar files with same format. I can import those in any order any time. The other files have different numbers of columns. Those I can only do one at a time.
I discovered that when I leave the import function and do something else then come back to import the out of range error clears. It's weird but after years of dealing with this stupid import error I have a workaround that doesn't involve closing out and
re-opening the database(s)!