Most recent cumulative updates come with broken patch

Jul 23, 2018 07:36 GMT  ·  By

Microsoft has recently confirmed that this month’s update rollout includes a botched patch that breaks down .NET Framework and apps, and Windows 10 devices are affected as well.

This means that if you install the most recent cumulative updates for Windows 10, you also get this issue, and Microsoft has updated the official KB pages to reflect this.

Basically, all July 16 cumulative updates are impacted, namely KB4345421 for Windows 10 April 2018 Update (version 1803), KB4345420 for Fall Creators Update (version 1709), and KB4345419 for Creators Update (version 1703).

Due to this issue, apps using .NET Framework fail to load with an error that reads access denied, class not registered, or internal failure occurred for unknown reasons. Microsoft says the most common failure signature is “Exception type: System.UnauthorizedAccessException. Message: Access is denied. (Exception from HRESULT: 0x80070005 (E_ACCESSDENIED)).”

No workaround

There’s no workaround for the time being, and Microsoft says that uninstalling these updates is the only way to restore functionality.

“Applications that rely on .NET Framework to initialize a COM component and that run with restricted permissions may fail to start or run correctly after you install the July 2018 Security and Quality Rollup updates for .NET Framework,” Microsoft explains in an advisory.

“The .NET Framework runtime uses the process token to determine whether the process is being run within an elevated context. These system calls can fail if the required process inspection permissions are not present. This causes an “access denied" error.”

The July 16 updates themselves were released to address issues in the original July 2018 updates published by Microsoft on Patch Tuesday. By the looks of things, the company would need to issue a third batch of updates this month in order to correct the .NET Framework issue as well.

At this point, no timing information is available on this new set of updates, but we’re guessing that Microsoft is working around the clock to develop a fix and it should be released as soon as possible.