Thank you for letting us know, Liza.
Let's do a few steps to get this sorted out.
First, let's use a sample sample file in your QuickBooks and create a backup copy from there. If it works using a sample file, let's rebuild your company file once more.
If you're still getting the same error message, let's try creating a different Admin user on your Mac computer. This is to determine if you have some system issues that prevent the software from creating a backup copy.
Also, if you're able to create a copy and you want to set up automatic backups, you can check this guide: How to schedule automatic backups of your company file?
Let's give this a shot and let me know on how this turns out. I want to ensure that this gets taken care of.
