What is the typical cause and remedy to address this error when i try to import old AMEX transactions manually? Darn. File upload failed. (Probably our fault.)

I'll help you with troubleshooting steps so you can import a file in QuickBooks Self-Employed (QBSE), @matthewsyzdek. 

When importing CSV files into QBSE, let's ensure all details are in the correct format to enable your file to upload in QuickBooks. 

Please take note that CSV files for credit card accounts may display transactions in reverse. For example, deposits may appear as negative amounts because paying your credit card reduces your balance. 

Then, if you get the same error message when you upload, do the following:

• Remove any zeros (0) from the file. Leave those cells blank.
• Correct any transactions that display numbers in the Description column.
• Remove the word "amount" if it appears in the Credit or Debit column header. They should only read "Credit" and "Debit" without the word "amount."
• Make sure the dates are in one format. We recommend you use: dd/mm/yyyy.
• Mac users must save the file as a Windows CSV file.
• Some banks add the day of the week in the Date column (for example, 20/11/2018 TUE). You need to remove the day of the week. To do this, split the date and the day of the week into separate columns:
  1. Open the CSV in Microsoft Excel.
  2. Highlight the column that contains the date.
  3. Go to Data then select Text to Columns.
  4. Follow the onscreen steps and select the following:
     • Original data type: Delimited
     • Delimiters: Space
     • Column data format: General

You may also have too much accumulated historical data. Whenever you visit a website, it saves some information from the web page in its cache and cookies. These files allow the websites you visit most often to load faster. Not to worry, clearing them will do the trick.

First, let's try accessing your account through an incognito window to rule out the possibility of a webpage issue. You can refer to these shortcut keys to open an incognito window in all supported browsers:

• Chrome: Ctrl+Shift+N
• Firefox: Ctrl+Shift+P
• Safari: Command+Shift+N

If the upload goes through, switch back to your regular browser. Then, clear its cache. This way, you can access QuickBooks with a clean slate. You can also use a different supported one.
 

Finally, review and categorize your transactions to put them in your accounts.

I'm always available at any time if you need further help with your files or any QuickBooks-related concerns. Don't hesitate to click the Reply button below or post in the Community again. Take care!