Hello there, @Spiderterp. I'm pleased to address your concern regarding QuickBooks Desktop (QBDT) for Mac 2021 and Sequoia 15.0.

Currently, there aren't any ongoing investigations regarding the compatibility of QBDT for Mac 2021 with Sequoia 15.0. If it's not running properly, it's likely because your system doesn't meet the minimum requirements, such as:

• A minimum of Mac OS X v10.15 (Catalina) is needed to install.
• A CD/DVD drive or internet connection is needed to download the product.
• Product registration is required.
• Intel processor, Core 2 Duo or higher.
• Multi-user Server: Intel Core 2 Duo or higher processor to run a server.
• 2 GB RAM (4 GB RAM recommended).
• 250 MB of available storage.
• Macintosh-compatible printer if you plan to print invoices, checks, deposit slips, lists, purchase orders, mailing labels, reports, or graphs.
• Use Intuit Checks if you plan to print checks.

For more detailed information, visit this article: System requirements for QuickBooks Desktop for Mac 2021.

To get QBDT to work on your new Mac OS, I suggest manually updating it to the latest version. This way, you'll have the newest features and fixes. Before doing so, be sure to backup your company file. Here's how:

1. In QB, navigate to File, then select Back Up.

2. Choose the folder to store your backup.

3. Click Start Backup.

Then, proceed to update your QBDT by following these steps:

1. Uninstall QB for Mac.

• Close QB.
• From the Finder menu, choose Go Applications.
• Drag the QB icon to the Trash.

2. Reinstall the latest version.

• Visit QuickBooks Downloads & Updates.
• Make sure to select the correct country, product, and version.

• Click Search, then Download.

• Double-click the .dmg file.
• Drag the QB icon to the Applications folder to install.

3. Restore your company file in QuickBooks.

Feel free to reach out again if you have any questions or concerns. I'm here to help. Take care and have a great day!