Boot Diagnostic setting needs to be applied to already created non profile based MCS random catalog.
To inherit profile based settings from a VM source to an existing catalog which is non-profile based 

 

Below Powershell script can be used to update the boot diagnostics settings and add a machine profile to the non-machine profile based citrix MCS catalog.

Please install the latest citrix cloud remote SDK for powershell and run the commands after authenticating to citrix cloud 

https://docs.citrix.com/en-us/citrix-daas/sdk-api.html

# [User Input Required] 
$provisioningSchemeName = "xxxxxxx"
$hostingUnitName = "xxxxxx"
$resourceGroupName = "xxxxxx"

# Run Get-ProvScheme to get the ServiceOffering used by the existing catalog and update the $newMachineSize
$newMachineSize = "Standard_******"
$updatedServiceOffering = "XDHyp:\HostingUnits\$hostingUnitName\ServiceOffering.folder\$newMachineSize.serviceoffering"

# Update the MachineProfile parameter to point to a VM source. ( This machine should have the Boot Diagnostics property enabled , the profile will be copied from this machine )

$machineProfileVmName = "win10profiletst"
$updatedMachineProfile = "XDHyp:\HostingUnits\$hostingUnitName\machineprofile.folder\$resourceGroupName.resourcegroup\$machineProfileVmName.vm"

# Modify the Provisioning Scheme 
Set-ProvScheme -ProvisioningSchemeName $provisioningSchemeName -ServiceOffering $updatedServiceOffering -MachineProfile  $updatedMachineProfile

Problem Cause

Updating MCS non-profile based catalog to profile based