Quickbooks Desktop no longer working after 26.1.2 upgrade

FYI, when the problem occurred for me all of the QuickBooks files were in the VM's local C: drive and the problem has already been identified as being caused by the November 2025 Windows 11 update which was incompatible with Parallels v21.1 or later. This has nothing to do with shared folders or drive mappings or with Windows permissions to the file location or with the file not being in the local VM C: drive. See https://kb.parallels.com/en/131061

 

Hey all,
Helping my mother-in-law get QB Pro 2021 installed in Parallels and running into an ever-loading activation screen which I'm chalking up to this bug. She was running 26.1 initially. Steps taken:
1. Switching emulation to Very Strict and rebooting the VM, no resolve.
2. Downgrading to 26.0.1 and re-activating did not resolve either (tried both default and very strict emu)
3. Ran QB as Administrator in all situations.
4. Windows Firewall was disabled the entire time.

Anything else I'm missing that's worth a try? I have an IT background and even I'm stumped! Hoping to see Quickbooks mentioned in the changelog on Parallels 26.1.3....

 

Unfortunately, the 26.2.0 update doesn't mention anything about fixing this interaction bug with the Windows update that breaks opening company files in QuickBooks Desktop. So after downgrading, you have to skip/ignore their upgrading request. You also need to turn off automatic updating in the Parallels Desktop - Preferences... - General - "Check for updates automatically". I suggest turning off Windows "Virus & threat protection settings" - "Real-time protection" since I find that having that on can significantly slow down installations. I don't know about activation, however, but it's worth a try.