Today I checked for iTunes updates (I was actually looking for IOS 15 for my iPhone) and it asked to update iTunes to the latest release (12.12.0.6).
After the update, I got this error message when starting iTunes:
I tried to repair the installation. No luck.
I uninstalled and reinstalled iTunes. Same error.
I uninstalled all Apple software as documented here, rebooted and reinstalled iTunes. Same result.
I uninstalled everything again and tried to install the version of iTunes distributed by the Microsoft Store (which I usually avoid). Even that doesn't work, same error message again.
OS is Windows 10 x64 21H1 with latest updates.
iTunes was running fine before the update.
Update
I tried installing iTunes on a fresh Windows VM which I had lying around (same OS release and updates, no other software installed), which never had any iTunes version installed or used on it.
I still received the same error and iTunes doesn't start.
This looks definitely like a seriously buggy release.