attempt to invoke method returns InvalidDataException: Missing required property about signalrcore HOT 2 CLOSED

I think that your error is related with the connection state. On the first snnipet that you provided contection is started but you are not waiting for the handshake. You need adding a callback method to your code. Once handshake is finished 'on_open' method is inovked

https://github.com/mandrewcito/signalrcore#on-connect--on-disconnect

You have a lot of examples on my post at dev.to and in the tests folder. If you continue having problems let me know :D

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oh, I see now! didn't expect start() to be non-blocking call. I was heavily affected by assumption that non-blocking calls are "marked" somehow, like in .net: startAsync() vs start(), which is silly thing to assume for other languages. I guess you right, and tickets I've read yesterday was about the same thing actually (connection state).
Thank you for such a quick reply! this should of been "stackoverflow" question, not a github ticket xD

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