@sfeld 

QBD 2020 has been outdated since last May and they will not release any more patches. You can run QBD 2020 on Sonoma 4.1 currently but your QB may crash again once Apple releases a newer update for Sonoma..If that happens, you can use a workaround to continue running QBD on your Mac. You can check the following reference for discontinuation of QBD 2021 to understand their 3-years policy.

https://quickbooks.intuit.com/learn-support/en-us/help-article/feature-preferences/quickbooks-deskto...