Let’s work together to get past the error so you can back up your company file in QuickBooks for Mac.

Let's make sure we meet the requirements for Mac Operating System (macOS) to be compatible with QuickBooks for Mac.

Computers update their OS every few years to improve their performance. Here, you’ll find out what OS versions work best for QuickBooks for Mac.

Supported versions:

• QuickBooks Desktop for Mac 2021 R3 and later versions
• QuickBooks Desktop for Mac 2020 R6 and later versions
• QuickBooks Desktop for Mac 2019 R9 and later versions

Then, install and make sure to download the latest released version of QuickBooks for Mac. Let me show you how.

1. Go to QuickBooks.
2. Select Check for Updates.
3. On the pop-up window, select Install Update.
4. Click Install and Relaunch.

But if you're still unable to open and work well with the program even after following the steps above, consider manually updating QuickBooks with the steps outlined in this article: How to keep QuickBooks for Mac up-to-date so you always have the latest features and fixes?

Also, Mac has a built-in disk utility that QuickBooks uses to create a DMG (image) file when backing up company files. We’ll need to verify the data to help detect the cause of the error, then run rebuild to resolve it. Just follow these steps and details in the Resolve data damage on your company file article. Once the rebuild completes, please verify the data again to ensure there aren’t any other issues in the company file.

If you’re still unable to back up the file, I recommend getting in contact with our QuickBooks for Mac Technical Support Team. They'll pull up your account in a secure environment and help you with this one. You may send a message via chat, call us at a time convenient to you, or we’ll get in touch with you instead. To ensure we address your concern, our representatives are available from 6:00 AM to 6:00 PM on weekdays and 6:00 AM - 3:00 PM on Saturdays, PST. See our support hours and types for more details about this one. Here's how:

1. Click this link: https://help.quickbooks.intuit.com/en_US/contact
2. Select QuickBooks Mac Desktop.
3. Select a topic and a sub-topic in step 1.
4. Click Get Phone Number in step 2.

Feel free to visit our Help Article page for more insights about running and managing your business in QuickBooks.

I'd like to know how you get on after trying the steps or if you are referring to something else. I want to ensure this is resolved for you. Just reply to this post and I'll get back to you. Take care always.