Resetting caches

Hi

I'm having a problem with the VSL plugin and Logic. When I use VI in a project file I cant always re-open the file. I thought I would try resetting some caches but I'm not sure which ones to do or why Im doing it! Also I dont wnat to mess anything up. Can anyone shed some light on this please? And giev me a bit of an outline as to what I should do?

Thanks