AppStream 2.0 VHD mount fail

Hello,

For past few days I'm trying to work with AppStream 2.0 app blocks and app builder and I'm running into issues which I can't solve. I created a test vhd called myapp.vhdx which contains my c++ compiled app that I would like to mount to my fleet machines to be able to run in it in background via script.

Myapp.vhdx and mount-vhd.ps1 is stored in S3 bucket eg. "mybucket" with below permissions

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "AllowRetrievalPermissionsToS3AppsForAppStream",
            "Effect": "Allow",
            "Principal": {
                "Service": "appstream.amazonaws.com"
            },
            "Action": "s3:GetObject",
            "Resource": "arn:aws:s3:::mybucket/*"
        }
    ]
}

I created an appblock called "test" with specified path to mount script, vhdx file, post setup script executable (powershell) and arguments (-ExecutionPolicy Bypass -file C:\AppStream\AppBlocks\test\mount-vhd.ps1). When I'm associating an app block builder to test if the VHD is properly mounted I'm getting such error

"Error during application deployment
The app block activation failed due to invalid volume type. Please use AppStream packaged VHD to create app block."  

and I'm running out of ideas what causes this issue.