https://wccftech.com/avast-fix-windows-10-april-2018-update/

We reported yesterday that Microsoft was blocking its latest Windows 10 April 2018 Update for PCs running Avast antivirus software after multiple reports of systems getting bricked. At the time, Avast had said that the two companies were unable to find what the issue was. The antivirus maker has now issued a new statement offering a fix for its users.

“In cooperation with Microsoft we have identified an element of the latest Windows 10 1803 update that is incompatible with the Avast Behavior Shield, causing the aforementioned update to fail in some instances (related to a timing issue, Internet connectivity issue, etc),” the company wrote.