Hello there, @ttime2.

Have you tried the steps shared by my colleague AlcaeusF? Or any error or prompt message when you review the file? 

In case you encounter an error, you can follow the steps on how to check the error.

1. Select Review now on the error message or prompt.
2. Search for the error.
3. Make corrections to the error.
4. Click Save.
5. Close the File not imported window.
6. Import the IIF file again.

Also, to import the IIF file successfully, you must double-check the account names used, the spelling, and any other typographical error. Ensure that the names used exist and are acceptable in QuickBooks.

For more details, you can check out this helpful article: Tasks You Can Do With IIF Files. 

However, if the issue persists, I'd recommend contacting our Customer Support Team. They can create a case regarding this matter. You can follow the steps shared by my colleague Ashley H to contact us.

To learn more about importing these files, and the maximum number of entries allowed, you may check out these articles:

• IIF Overview: import kit, sample files, and headers
• Import IIF Files
• Maximum number of QuickBooks Desktop list 
• Improved IIF Import in QuickBooks 2019 and later.

Please stay in touch with me if you have other questions. I'm here to help however I can. Have a great weekend!