Need urgent help! Cubase slowdown when GUI open

Hey guys

Im having the strangest day and really hope someone can help me.

Running latest Cubase (x64) on Win 7, latest driver etc etc. There have been no Hardware changes. I did not install any new software. Nothing.

Cubase now stutters and slows down when loading a plugin. Not the plugin itself but when you click on E to bring up its GUI. Once the gui is visible, everything slows down. I have a video because it shows this best. In this video, a fresh arrg, ONE plugin and nothing else. Unbelievable:

I cannot work like this, having everything slow down and stutter only to use a plugin. This came out of nowhere as yesterday everything seemed fine.

I wanna cry :frowning: :cry: