When I start the game, click on "Multiplayer" and doubleclick on a server, the game crashes immediately and creates a crashreport on my desktop.

Without posting the crash report here we cannot help you. We make these things for a reason!

Same problem here, but it doesn't even give me a crash report, it just closes silently.

Clicking on "Join Server" works fine most of the time.

Cannot reproduce.
Please attach the crash report, otherwise this issue will be closed.

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