Unexplained Hammer Crash

When I open Hammer Editor, it runs fine. Then, I open object properties. Still fine. I go to change the world model for a prop, and search: ‘tr’. CRAAAAAAASH. Can anyone give me some insight as to why this might happen?

Happends a lot. No real explanation.

Please, use the two megathreads specifically for these sort of questions.
http://www.facepunch.com/threads/602394-The-Mappers-Encyclopedia-Section-Rules-Question-Megathread-(Read-Before-Posting)
and
http://www.facepunch.com/threads/972022-Mapping-Question-Mega-Thread

Well, for example, when I click on “NYPD Hats”, my Hammer crashes.
Something with some props.

Towel don’t tell people to do that when the question has already been answered.

Towels done that in a few threads now, trying to be Mr big and helpful when he can’t just answer questions himself :v: