AE CC18 freezing but App not frozen

Hey guys,

I'm kinda close to a nervous break down with After Effects at the moment,

It doesn't seem to make any sense to me. After Effects itself is not frozen at all, all buttons work and I can look through the projects etc., but nothing is reacting.

For example if I change the preview size (25%...50%..100%) the window remains the same size, even though it shows a different percentage value.

And then, maybe after 1 minute or two, the preview gets updated and I see the changes I made. But it's not like it's buffering or calculating, the things I do are super simple at the moment

and don't require any calculations, it also doesn't matter if I preview in Software only or CUDA, it doesn't matter how high or low my preview res is, it simply doesn't work?!

Any ideas appreciated.

Windows 10 Pro

Intel Xeon CPU E5-2630 v4 @ 2.20GHz

64GB RAM

Geforce  GTX1080

After Effects Version: 15.1.2 (Build69)