Unable to reinstall QB 2019 for Mac on my MacBook Air

Hi there, Shelyon.
 

I understand how frustrating it must be to encounter these issues. Please know that QuickBooks Desktop 2019 for Mac is a discontinued version, which means it no longer receives updates, fixes, or customer support.

The main reason you can no longer open the app is due to subscription support ending and compatibility issues with macOS. Since QuickBooks Desktop 2019 for Mac is no longer a supported version, it may not work with newer macOS versions (e.g., Big Sur, Monterey, Ventura, or later). Running outdated software on modern macOS versions often causes errors, as the system can no longer support the older software.
 

If you'd like assistance with this issue, you may contact your IT personnel for further support. 
 

However, if you want software that is supported and compatible with your current macOS version, I recommend upgrading your subscription to the latest QuickBooks Desktop version available on our pricing website. You can also contact our Live Support Team for other options.
 

Please leave us a response if you have further questions or concerns.

@Shelyon 

Can you login to CAMPS and find your license code there?

https://camps.intuit.com

Another option, you can use the trial version as a workaround.

Hello @Shelyon , your disc might be an older release than what your current operating system may support.  What you can try is going to the following site and downloading an updated copy of your QuickBooks 2019 and installing that one, it's the QuickBooks Mac 2019 R15 version.  On the site just choose US, QuickBooks Mac and the 2019 version.

https://downloads.quickbooks.com/app/qbdt/products