Hello there. I'm here to share some insights about the error you get when uploading web connect files to QuickBooks Desktop (QBDT).

Importing the *.qbo file is no longer supported by any outdated QBDT version. Since QBDT 2020 is one of the unsupported versions of QuickBooks, the ability to use the bank feeds feature is also discontinued. This might be the reason you're getting an error when trying to upload. For reference, please check this article: QuickBooks Desktop 2020 service discontinuation policy. 

That being said, you may consider upgrading your QBDT program to a newer version to import web-connect files seamlessly. Another option is to switch to QuickBooks Online (QBO) and connect your bank account there. 

For more reference on fixing web-connect import errors, feel free to check this article: Fix Web Connect import errors.

I also include this helpful resource that you can use as a guide in managing and categorizing your transactions in QBDT: Add and match Bank Feed transactions in QuickBooks Desktop.

I'm always here ready to lend a hand if you have any other concerns managing your bank transactions. Have a good one and stay safe.