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Hello everyone,
I am trying to setup App Attach for my organization and I'm running into some issues.
I am using a self-signed certificate and have signed 2 test packages using that. (I tried with VHD first and then with VHDX)
I also added the certificate as trusted on both session hosts.
I am able to deploy the app from the portal after I make these changes, however the app I am deploying never installs on either session host.
I am able to see the package files in the E:/ drive under apps but it isn't available for use.
Based on the event logs it's successful in the deployment too.
I've checked the permissions in the Portal and in the session hosts, I am able to manually mount the image and ran multiple connection tests to the file share which were all successful.
I have also made sure that the only dependency for my packages (Windows App Runtime 1.4) is running on the session hosts.
I feel like I am missing something here for the deployment not to work.
I am not sure if this is relevant but I am deploying this to a Windows Enterprise 11 24H2 Image with enabled FSLogix.
I would appreciate any suggestions for this or any steps that I may have missed.
Thank you in advance!
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Hi Alex Dresser,
Could you please let us know below information:
Are you managing your session hosts through the Azure Virtual Desktop blade in the Azure portal?
Could you clarify the steps you followed for signing and uploading the MSIX packages?
Are there any specific error messages in the event logs on the session hosts related to the app installation?
Hey @Anusree Nashetty ,Are you managing your session hosts through the Azure Virtual Desktop blade in the Azure portal? - If I go to the Azure Virtual Desktop blade - Host Pools I can see the host pool with my session hosts, yes.
Could you clarify the steps you followed for signing and uploading the MSIX packages? - I created a self-signed certificate from Powershell and after that I used that certificate to sign the MSIX package. I made sure to export the .cer file and add added it to Trusted people in the session hosts and in the file share in the Azure Portal.
Are there any specific error messages in the event logs on the session hosts related to the app installation?
6/3/2025 10:42:51 AM 603 Started deployment Register operation on a package with main parameter
AppxManifest.xml and Options 0 and 0. See
http://go.microsoft.com/fwlink/?LinkId=235160 for help diagnosing app
deployment issues.
6/3/2025 10:42:51 AM 709 Rejecting a request to register from AppxManifest.xml because the manifest is
not in the package root.
6/3/2025 10:42:51 AM 404 AppX Deployment operation failed for package with error 0x80070057. The
specific error text for this failure is: Rejecting a request to register from
AppxManifest.xml because the manifest is not in the package root.
Hi Alex Dresser,
Thanks for getting back to us. The Error **Rejecting a request to register from AppxManifest.xml because the manifest is not in the package root **indicates that your MSIX package is malformed - the AppxManifest.xml file must be at the root of the package, but your package appears to have it in a subfolder.
The MSIX package you uploaded does not have AppxManifest.xml at the root of the virtual disk structure (the VHD/VHDX or CIM file), which is mandatory for MSIX App Attach to work. When the system tries to "register" the app (i.e., mount and publish it), it cannot find the manifest at the expected path.
Ensure the folder structure inside the MSIX file is flat — meaning AppxManifest.xml should be directly at the root, not nested in a subfolder.
If the manifest is misplaced, you can recreate the package.
Make sure the certificate used to sign the MSIX is still trusted on the session hosts. Ensure the file share is accessible from all session hosts and registered in the Azure Portal.
For detailed information, please check: https://learn.microsoft.com/en-us/windows/msix/package/packaging-layout
https://learn.microsoft.com/en-us/windows/msix/desktop/app-attach-from-visualstudio?source=recommendations
If you have any further queries, let me know. If the information is helpful, please click on Upvote.
Hi Alex Dresser,
Did you get a chance to see my response. If you have any further queries, let me know. If the information is helpful, please click on Upvote.
Hey @Anusree Nashetty , I tried what you suggested before but it didn't help. This is working now - I had not created a Remote Application group and after I did that the apps are visible.
Hi Alex Dresser,
Thanks for sharing the resolution.