I just spent the last hour bashing my head against my keyboard trying to figure out what I had done wrong in one of my scripts.
It turns out when you are inside a Switch construct, the variable $Switch value is redefined (presumably by the switch construct itself) as an empty variable of type System.Collections.IEnumerator. The value is set to $null. This won’t be a problem if you’re not using a variable with the name $Switch. Unfortunately I was because I was working with a set to Virtual Switches so $Switch seemed like a fair choice of variable name.
I could go and research further into this and find out why this is, but I just don’t have time right now. If anyone else has looked into this I’d be really interested to know why.