Thanks for joining in this thread, @c3087. I can help you fix the errors.

When there are corrupted data, we can recover all or nearly all of your data with the use of QuickBooks Auto Data Recovery (ADR) tool. Please note that the process can take some time. 

ADR can help you recover your lost file by:

• restoring lost transactions using your current Transaction Log file and a copy of your Company file.
• restoring all but the last few hours of transactions with a copy of both your Company file and your Transaction Log file.

Here's an article with more detailed steps on recovering lost data: Recover lost data with QuickBooks Auto Data Recovery. 

For future reference, read through this article: Export, import, and edit IIF files. It'll help you learn about moving data to and from QuickBooks Desktop. 

Looking forward to helping you again if you need further assistance. Take care.