The NPM package building the artifacts is using the following for the parameter file name (notice ARM is all caps).
ARMTemplateParametersForFactory.json
Line 551 of the PrePostDeploymentScript.Ver2.ps1 script to bulid the path for that file when not provided uses:
$ArmTemplateParameters = Join-Path -Path (Split-Path $ArmTemplate -Parent) -ChildPath 'ArmTemplateParametersForFactory.json'
This fails to find the file due to the case mismatch in the filename, mixed case of "Arm" instead of "ARM".
Can this be adjusted to address the issue?
It only causes problems on a linux based agent. Windows agents seem to be case insensitive and this doesn't cause a problem.