VST support seems to be a hit and miss thing. The only advice I've ever seen for crashes involving specific VSTs is "don't use that VST". I usually hunt around until I find an alternative that works. Always best to go for ones that have free demos so you can check that they work before buying, if it's a commercial VST.
Also check that you're trying to use a VST 2.0 plugin as OBS does not support VST 3.0 plugins.
If you are using commercial plugins, it's worth using a combination of third party host applications (I use both the free Hosting AU application and the commercial Blue Cat's Patchwork app, in combination with LoopBack to get virtual devices, to host VST and AU plugins to process audio before bringing it in to OBS for when I need to do something that OBS can't do, such as work with a plugin that isn't stable within OBS.
