Last night I used PowerShell to deploy a Kubernetes cluster on AKS with something like this:

New-AzureRmAks -ResourceGroupName "my-rg" -Name "my-aks-cluster" -KubernetesVersion "1.16.13" -NodeCount 2 -NodeVmSize "Standard_DS2_V2" -Verbose

This worked fine. Today, however, I tried this same thing in a different subscription, but keep getting the following error:

VERBOSE: Cluster does not exist.
VERBOSE: Cluster is new.
VERBOSE: Performing the operation "Creating a managed Kubernetes cluster." on target "my-aks-cluster in my-rg".
VERBOSE: Preparing for deployment of your managed Kubernetes cluster.
VERBOSE: Using location eastus from the resource group my-rg.
VERBOSE: Using DNS name prefix my-aks-cluster-my-rg-dcdf2a.
VERBOSE: Fetching SSH public key from file C:\Users\myuser\.ssh\id_rsa.pub
New-AzureRmAks : The given key was not present in the dictionary.
At line:1 char:1
+ New-AzureRmAks -ResourceGroupName "my-reg" -Name "my-aks-cluster" -Kube ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : CloseError: (:) [New-AzureRmAks], KeyNotFoundException
    + FullyQualifiedErrorId : Microsoft.Azure.Commands.Aks.NewAzureRmAks

I'm confused because: 1. This same command worked earlier 2. I have same admin rights to new subscription as to the one previously used 3. The path to the key is valid 4. The key, id_rsa.pub, is at the path listed

Anyone have an idea what is going on here? Any tips are appreciated.