Had the same problem on one of the computers in our makerspace. Running the regsvr32 command did work just fine here. Did have to temporarily install it on another pc (but NOT click the option to restart explorer to get the thumbnails working, because that is what caused the crashing) to get the path though. So for anyone else's reference the path should be something like "C:\Program Files\ChiTuBox64 18.104.22.168 Beta" or 32 if you aren't installing the 64 bit version.
I also have the same problem, I am attaching the video https://youtu.be/XmHJZBwqGsE , I solved it by deleting C:\Program Files\CHITUBOX64 1.7.0\CHITUBOX_Thumbnail.dll Also Chitubox does not work with the Intel HD 630 integrated video card and I have to force the use of the dedicated Nvidia GTX 1050 mobile video card.