Welcome back to the Community, @anonimus.
This error occurs when the mapping of your CSV file is incorrect. Make sure to enter the right columns in the mapping stage so that QuickBooks Online (QBO) will read the data.
QBO can import CSV files that use either a 3 (Date, Description, and Amount) or 4-column (Date, Description, Credit, and Debit) format. Change the names to match the titles in the system. Check out this article for the sample template format: Import bank transactions using Excel CSV files.
Just in case, I'll add this article for future reference: Common errors for importing bank transactions using CSV.
Please let me know in the comment below if you have any other issues or concerns. I'm always here to help. Have a good one!