QB Mac Desktop

I got your back, @GR Tavares.

Updating your QuickBooks Desktop (QBDT) for Mac is a good start in resolving program-related issues. Let me guide you how:

1. Click the QuickBooks drop-down menu and select Check for QuickBooks Updates.
2. Select Install Update, if a newer version is available,
3. Then, click Install and Relaunch.
4. Once done, QuickBooks for Mac automatically opens.

For your reference about the process, please visit this article: Update QuickBooks for Mac to the latest release.

If the same issue persists, you can also run the Verify and Rebuild utility that helps identify and resolve data integrity issues.

Once everything is fine, you're now ready to enter bills in QBDT.

Just in case you'll have to enter refunds you received from a vendor, you can easily do it in QBDT for Mac. For detailed instructions, check out this link: Record a vendor refund in QuickBooks Desktop.

I'm always around here in the Community if you have any other QuickBooks-related concerns. Don't hesitate to leave a reply below. 

I think I've heard of this happening if there are no accounts payable in the chart of accounts.  If that's the case try adding one.