my mlat is switched off since 11:30 utc 23.12.2015

my mlat is switched off since 12:30 utc 23.12.2015

Looks like it is still enabled and you have sync, but stats are showing zero results, so I guess this is a bug report? Some details would help.

edit: you have three connections with the same MAC address to the same mlat server. That’s either duplicate piaware processes (though I’m pretty sure that should be impossible now) or you’re still running multiple feeds with the same MAC. I did warn you that doing that was likely to break stuff, and I guess that it has managed to confuse the mlat server somehow. Before I spend more time diagnosing this, can you check for stray piaware processes and make sure you’re using a separate MAC for each feed?