This can be a browser-related issue @ joannamidolo.

Let me provide some basic troubleshooting steps to fix this issue.

First, use a private window to access QuickBooks. This will prevent the use of cookies stored on the computer.

Let's simply press the following commands:

• Ctrl + Shift + N (Google Chrome).
• Ctrl + Shift + P (Firefox or Internet Explorer).
• Control + Option + P (Safari).

Once done, you can try converting again. If it works, then let’s go back to your browser and clear the cache. These caches of data are essentially junk files and can be safely deleted to free up storage space.

I also recommend using other supported browser in QuickBooks if the issue persist.

However, if you're still getting the error, it would be best to get in touch with our QuickBooks support team to further assist the issue.

Here's how:

1. Select Help (?) at the top right.
2. Click the Contact Us button.
3. Enter "Convert my QuickBooks Online to QuickBooks Desktop" in the description.
4. Hit Let's talk.
5. Select Get a callback.

You can comment below if you need anything. I'm here to help.