I'm testing a migration from the old Azure Slaves plugin to the new ARM plugin.

I've got a Linux deployment working properly, with SSH & an an init script on top of a fresh Ubuntu VM (i.e. NOT using disk capture on a previously configured VM). Trying to achieve similar on Windows, however, yields the following:

{{INFO: AzureVMCloud: createProvisionedAgent: Waiting for deployment wintest0124162232263 to be completed
Jan 24, 2017 4:23:13 PM com.microsoft.azure.AzureVMCloud$3 call
SEVERE: Failure creating provisioned agent 'wintest9c51a0'
com.microsoft.azure.exceptions.AzureCloudException: AzureVMCloud: createProvisionedAgent: Deployment Failed: Microsoft.Compute/virtualMachines:wintest9c51a0 - BadRequest
at com.microsoft.azure.AzureVMCloud.createProvisionedAgent(AzureVMCloud.java:410)
at com.microsoft.azure.AzureVMCloud.access$100(AzureVMCloud.java:69)
at com.microsoft.azure.AzureVMCloud$3.call(AzureVMCloud.java:547)
at com.microsoft.azure.AzureVMCloud$3.call(AzureVMCloud.java:533)
at jenkins.util.ContextResettingExecutorService$2.call(ContextResettingExecutorService.java:46)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)}}

The BadRequest implies a config issue, but the template validates fine, and I can't see any obvious mistakes in what I'm doing. I'm attaching both config xml fragments. Is there some lingering problem with deploying non-captured Windows images in the new plugin?