"No connection is available to service this operation: GET"
"It was not possible to connect to the redis server(s); to create a disconnected multiplexer, disable AbortOnConnectFail. ConnectTimeout"

Redis, running on Windows with the default settings.

The problem? ssl was set to true in the connection string but not setup on the server. I set ssl to false (it is only for development) and it all works fine. Why would this not return a useful error like "ssl not setup on server"?

We only found out when one of our Devs happened to spot the ssl setting and wondered if that was why it worked in production and not in dev!