It's good to see you here in the Community, companies-bothus. Allow me to share some information regarding the uploading CSV file in QuickBooks Online.

The error message you're getting occurs when the mapping of your CSV file is incorrect. Make sure your file has all the necessary information and enter the right columns in the mapping stage so that QuickBooks Online (QBO) will read the data.

Below are a sample of a CSV file and the mapping section in the program:

After you map the transactions correctly, you'll be able to upload them smoothly. Once imported, I recommend editing, assigning, and categorising your transactions. Also, you can match them to the existing entries in the software. Just go to the For Review tab from the Banking menu. Doing so will help you ensure the accuracy of your financial records.

I'm only a post away if you have any other questions about this topic or anything else you need help with QuickBooks. I'll be glad to share and provide further assistance whenever you need one. Have a nice day!