Welcome to the Community, 

@alan_mt. This isn't the experience we want you to have. Let me share some information about uploading a CSV file to QuickBooks Online (QBO).

To successfully import your CSV file to QBO, you must use the correct formatting. If you do not follow the correct format, QBO may not recognize the file. It's important to note that each bank's CSV file format is different, so you may be unable to import CSVs from certain banks as their files may need a different format than QuickBooks.

In case your bank doesn't export to a CSV file, you can still upload your statements to QuickBooks Online via Quicken (.QFX), QuickBooks Online (.QBO), or Microsoft Money (.OFX) files as long as they follow the correct format.

The 3-column format

This format has a Date, Description, and Amount column. 

The 4-column format

This format has a Date, Description, Credit (money out), and Debit (money in) column. 

After checking the format, please import the transactions again.

Once you've successfully imported the transactions, you can now reconcile the account.

Let me know if you have other queries about importing your files. I'm here to lend a hand. Have a great day.