Alternative to Quicksilver Triggers
You are not alone in this problem and in fact I bought Alfred as part of addressing this problem.

It looks like there are some other users still trying to get Quicksilver working, and even though it is not really in active development, there is an article on how to download two different versions of Quicksilver, and then selectively deleting or merging files together. 

Honestly, given this level of annoyance, I would go with Alfred.