I figured I do a quick blog post on the topic of VCSIM and VCSA 6.0 since I have received several questions regarding its functioanlity in VCSA 6.0. The simple and unfortunate answer is that VCSIM no longer functions in the latest VCSA 6.0. There have been enough changes to the vSphere 5.x and vSphere 6.0 code base that this internal tool will no longer function. As far as I know, there are no plans of changing this as VCSIM was primarily used internally by our Developers for certain types of functional testing. I know I will miss using the tool as it did come in handy!
UPDATE (04/23/17) - For those interested in VCSIM, there is a new project called govcsim. For more details check it out here.
VCSIM should continue to work in both VCSA 5.1 and 5.5 and you can find more details in the articles below.