It happened to me with earlier releases of KStars but has not happened yet on the 3.6.2 beta I'm running now. From what I remember, "find tool" KStars crashes did not always happen but was a kind of hit-and-miss thing, it could crash Kstars if I used the find button but not the ctrl-f keyboard shortcut and vice-versa. It was then crashing more often than not though. IIRC I think someone looked at the problem a few months ago but I don't remember about the details.
So I just did a
sudo apt-get -y install ekos-debugger
sudo apt-get -y install gdb
and chose the stable release and then my latest compile from source (as in my previous post) to launch in ekosdebugger. Both launched without a problem and the Find function worked.
After that, launching them without using the debugger also worked (i.e. the find Function worked).
Not sure what the installs tweaked, but something was kicked into working.