To help with troubleshooting and diagnosing issues with MSIX app attach packages on WVD, I have added some features to my MSIX Event log tool which helps you review the events from the RDAgent on Windows Virtual Desktop specifically for MSIX app attach.
There are three options just like the first version of MSIX logs. View, Export, and Clear.
As shown in the screenshot below, you can see the MSIX App attach Log file functions added to this tool.
Output:
As you can see from the screenshot below, its very easy to see what’s going on under the hood. If MSIX images have been staged, if a package has registered correctly. This is very useful when trying to understand why apps are not appearing for users.

Also for additional support purposes, I have included the ability to output the log files to c:\logs folder on the session host.

Summary:
I hope this helps with your MSIX app attach journey and if you ever need to find out what’s erroring and want to understand what the RDagent is up to, this tool will help you solve any issues that may occur.
You can download the app Here: Download Me
You can also read more about MSIX app attach here >>> My MSIXAA Wiki