What is that scom agent install error again?

There are so many things that can go wrong when trying to push a SCOM agent to machine. And of course my list of favorites grew so large that I had to go and find the article by Kevin Holman again. Just to make sure… here it is:
Many many thanks to Kevin (actually you can keep saying that to him a lot of the time) :p
And while I am at it, also check this post on agent error troubleshooting by the same :>>.