You will not be able to upgrade Windows 10 if you are using the old version of AVG, Avast applications

Microsoft has recently announced the addition of a new feature, allowing Windows 10 to automatically lock the update to version 1903 or 1909 if it detects Avast or AVG Antivirus antivirus software on the system. Your system is in an outdated version. After you update your antivirus software to the new version, everything will be back to normal.

Specifically, if you are using AVG or Avast Antivirus applications versions 19.5.4444.567 and earlier, you will not be able to install Windows 10 May 2019 Update (1903) and November 2019 Update (1909). The reason given by Microsoft is as follows:

'Microsoft and Avast have identified compatibility issues between several versions of Avast Antivirus as well as AVG Antivirus and Windows 10 versions 1903 and 1909. Any Avast or AVG Antivirus applications version 19.5. 4444,567 and earlier were affected, so the decision to block the update of new versions on Windows 10 will be applied until users upgrade their antivirus software to a newer version to ensure that Back to the best experience for you. '

AVG also issued a similar notice:

"Starting November 2019, the AVG Antivirus app version 19.5 and below will no longer be compatible with Windows 10 version 1903 (May 2019 Update). Before your PC can update to this version of Windows 10, Set up dialog box will display the applications you need top attention. If AVG Antivirus appears in this dialog box, please refer to the related instructions below to install the latest version of AVG Antivirus ".

This will affect versions of AVG Antivirus FREE, AVG Internet Security, Avast Free Antivirus, Avast Pro Antivirus, Avast Internet Security and Avast Premier. This is a relatively aggressive move by Microsoft after a series of reports from users about the compatibility problem between AVG and Windows 10 antivirus applications.