SREK beat me to it but I'll add my response regarding the plugins specifically....
best bet is to troubleshoot by dragging your plugins folder (in your preferences folder) to the desktop and restart C4D. See if it loads up just fine. Next, start adding back some plugins and restarting. Keep adding back plugins. I'm guessing however it's Redshift as you mentioned Redshift in your post. Leave that one out for last. It could be legacy Redshift is having issues with the new drivers. You may have to roll back.
If I were you, I'd consider adding a couple of SSD cache drives to that build. I'd also upgrade the OS drive to 1TB, given the prices are low at the moment. FInally, I'd also double up to 128GB RAM if at all possible.
Otoy, Octane big deals.
OctaneStudio+ Ultimate Black Friday Bundle Now Available!
Featuring Greyscalegorilla+, Mol 3D, Cascadeur, KitBash3D, World Creator, EmberGenFX, MetaFaces and more.
OTOY • OctaneRender: Purchase