Weird lag for no reason ?

Hi!

I got Serum with Splice since 4 month now and until today i've had no problem. 

Today for some reason my Cpu usage got to 99% and then music stop and start "loading" like a YouTube video.
apparently the problem is the "unison" when I down it to 1 the lag stop, but it sound bad. 
Why Serum do this now ? Yesterday i got no problem!

My CPU is ok I guess : I7 5820k 
i really don't get it can someone help me ?

Thank!

It's probably something unrelated to Serum, you could email me the project file if it is project specific -> [email protected]
otherwise make sure your soundcard and samplerate settings have not changed, and if it is a laptop make sure it is plugged in (charging).