Happened on 4.8 and still trying to get 4.9 running, but looks like it does the same thing.
If i have a shortcut on my desktop, a huge file called core is created.
If i run from the command line, it appears in my home folder.
If i run from my project its then in the project file…
It would be nice if this file was kept with the UE4Editor binary or Project if its project specific, and didnt keep appearing all over the system like it does…