Avast Virus Definitions Not Updating. The error can be due to a bug or because of a. The major reason for Avast not updating the virus definitions is incompatibility issues.
The availability of a new version is. Make sure the Updater is allowed by your firewall. It doesn't matter whether you are using the premium version or the free one; people are having the issue on both of them.
That's all, I hope this article covered all the major.
Note that Avast (like most reputable AV tools) release software updates twice a week.
Your Avast version may not be compatible with the Windows This can occur if an update failed or was canceled during installation. Depending on why the error is. To manually update virus definitions just run the vpsupd.exe file you can download from this.