Just a FYI. This has already been fixed here, but I’m working on a other fixes before releasing an update.
A pity that we missed that one during the betas, but I suppose playing lots of different plugins on a single track at the same time isn’t something that one often does…
Except lot of times. 
Problem is that in most cases these crashes are overlooked and users blame plugins (after all after project reload, user can add new vst).
I must made several tests to be sure it’s not plugin problem but Renoise.
In my experience it’s most likely the plugin, not renoise. I tried the free Quetzalcoatl synth yesterday and it crashed renoise badly and even the file explorer was hanging after quitting.I use Reaper to crosscheck for that purpose. Reaper is rock solid and if something crashes there, it’s a bug in the plugin.
For some reason, it also has significantly less CPU usage than any other DAW. I made a patch in Softube Model 72 that was around 30% in other DAWs including renoise, but only 5% in Reaper. The JV8080 emulator has 25% without doing anything in renoise and MuLab10, but only 2% in Reaper. Weird.
Correction: The RT CPU usage in Reaper is about the same. I guess the “anticipative fx processing” of reaper does something, but renoise is generally about the same.
taktik (Renoise’s developer) said few messages before he fixed it and it will be shipped in the next release when he finished working on a few other issues, so in that case it seems it was a Renoise edge case