Hi there, @WR11211. Thanks for reaching out and providing a screenshot of the error message that your contractors encounter. 

As per checking our tools, there was a previous investigation about the error message that you're contractor received that is already closed and resolved. But since they still encounter the problem, I suggest reaching out to our QuickBooks Support Team. They have the tools to further check the root cause of this issue and might raise an investigation.

To reach them, click the ? Help button at the top-right corner of your QBO account and select Contact Us to talk with a live agent. Ensure to review their support hours to know when agents are available.

For future reference, I've got you this helpful article in case you need some ideas about your contractor's 1099 forms and payment: Get answers to your 1099 questions.

Let us know if you have any other concerns. We're here to help.