This error message means it failed to send a heartbeat packet to the target mudfish node <node name>. However if its error level is "[INFO]" not "[ERROR]", you can ignore this error message because it doesn't affect your connection = Solution = * Please try to change a mudfish node <node name> to others * Or please try to change "Connection Protocol" found under   "Setup -> Program" menu. * Or please contact to the mudfish forums.

[60.850420] [ERROR] MUDEC_00235: Too many heartbeat errors. Blocked by network firewalls? I can see errors now. BTW，I based in China recently. Seems I have problems with connecting to master servers.

Ooops..  :-(  Then did you try to change Connection Protocols to another?

Sure. Only TCP 443 can work sometimes.

Weird...  Are you under network firewall then?  Without thinking of firewalls, I can't imagine what it causes.

Sorry. I find out TCP can work. Not only 443. But not UDP.