Some users who’re using Avast Antivirus as a security app on their computer reporting that after installing Windows 10 Cumulative update KB4557957, whenever they trying to launch the app, especially Microsoft Office, Edge, and other apps, they see an error message which reads : You can check this Microsoft Microsoft Thread and Avast forum this to get more information from the users reporting about the issue. Both Microsoft and Avast are aware of the issue. Even Avast has already released the update to fix the issue. In case, you don’t want to wait for the update to reach your computer, then you download the installation page from this link to install the product with a fix manually. Due to any reason, if manually installing the update fail to fix the issue, then you can try following registry hack to fix the issue: Launch Registry Editor on your computer. For that, type regedit in start menu search bar and when result appear in search results click to open it. In Registry Editor, you need to navigate to Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options Here on the left pane, you will get list of all the app which you have installed on your computer. You need to delete the folders of the apps that isn’t opening. Since its issue from Avast, you don’t need any update from Microsoft related to Windows and Office to fix the issue. Are you affected from this issue? What helped you in fixing the issue? Let us know in the comments.