Earlier today, Microsoft posted this advisory on the official MSDN .NET blog:
The July 2018 Security and Quality Rollup updates for .NET Framework was released earlier this month. We have received multiple customer reports of applications that fail to start or don’t run correctly after installing the July 2018 update.. A COM component fails to load because of “access denied,” “class not registered,” or “internal failure occurred for unknown reasons” errors.
We have stopped distributing the .NET Framework July 2018 updates on Windows Update and are actively working on fixing and re-shipping this month’s updates…
Temporarily uninstall the July 2018 Security and Quality Rollup updates for .NET Framework to restore functionality until a new update has been released to correct this problem.