Microsoft has just discovered a new compatibility issue with older versions of Avast and AVG anti-virus and the latest versions of Windows 10 (via ZDNet). On the Windows 10 Health Dashboard, Microsoft indicated that "any application from Avast or AVG that contains Antivirus version 19.5.4444.567 or earlier is affected.”
The software giant has put new upgrade blocks in place to prevent machines running older versions of AVG and Avast from installing Windows 10 version 1903 or 1909, and it’s also asking affected users to not install Windows 10 version 1903 or 1909 manually. "Before updating to Windows 10, version 1903 or Windows 10, version 1909, you will need to download and install an updated version of your Avast or AVG application,” the company explained. Another workaround would be to uninstall these apps and switch to Microsoft’s own Windows Defender antivirus, which is now just as good as third-party solutions.
Microsoft previously blocked the upgrade to Windows 10 version 1903 and 1909 on older devices with outdated Qualcomm and Realtek drivers, which could problems with Bluetooth and WiFi connectivity. These two compatibility issues have been fixed earlier this month following the release of updated drivers.