More information would be helpful

Trust?, Estate?, Initial Return? Fiscal year selected on Info Page?

Lots of variables.

9/5/2020 is an oddly specific date that doesnt correspond to any deadline...is this a fiscal year return?  

Now I see it's "2020" or did you type it wrong and it is 9/5/2021?

I was thinking that the program may not let you extend until within 10 days of what it thinks the deadline is, but the original post says Last September so I really am lost at this point.

2020 is correct, but should have been 9/15/2020.

My post should have read "9/15/2020, but yes a mystery.