What's this "Buffer overflow in net message" bullshit?

[Honeycoin]

I'm trying to play Machine Hell, on Pyro, with a team of other people on the server, and right after a wave fails, I'm the one that gets kicked off with this fucking error ... repeatedly!  So, why can't I play as [CLASS NAME HERE]?

Also, what's with this arbitrary rule that you can't change classes during a wave?

[VoiDeD]

I'm trying to play Machine Hell, on Pyro, with a team of other people on the server, and right after a wave fails, I'm the one that gets kicked off with this fucking error ... repeatedly!  So, why can't I play as [CLASS NAME HERE]?

That issue isn't related to what class you're playing, just that there's often too much networking going on during MvM that some clients will get dropped with this error. Valve(TM).

Also, what's with this arbitrary rule that you can't change classes during a wave?

Isn't that the default behavior of MvM?

[Punishment_Fatal]

Isn't that the default behavior of MvM?

Yes. I believe it's because Valve doesn't want, per say, a Medic switching over to Soldier in the middle of the round and making it easy by powering up the team when it needs it.