I am facing the issue that when I host a WebVI on SystemLink Cloud, I get error -251042 when I try to create a message session with the server with the SystemLink API when I feed in a configuration where I don't enter credentials (since the WebVI is hosted on SystemLink Cloud). I don't get this error when instead of sending and receiving messages, I try to read or write tags. The Call SystemLink Data Services example (https://ni.github.io/webvi-examples/CallSystemLinkDataServices/) gives the same problem when deployed on SystemLink Cloud. Tags work just fine, but trying to send or receive messages fails.
The error disappears when I do enter an API key to open the configuration.
My question is if this is expected behavior? My understanding was that I did not have to supply an API key to a WebVI hosted on SystemLink Cloud. I also wonder why I don't have this issue with the tags and only when trying to use messages.