Can't log into servers.

[Cascore]

I have Plumble on a Samsung Galaxy SIII I haven't been able to log into any servers. Every time I try, it tells me to check my certificate settings. All I can think to do there is generate a new certificate, which I've wound up doing multiple times, but it never works and I always get the same error. I'm not sure if this is just an issue with my phone, but I can't find any way to get around this problem.