Why did my UE4 project crash?

"We apologize for the inconvenience.
Please send this crash report to help improve our software.

21fff7ed4282faeeababbc4d3a2f7bba"

Someone has any ideas?
work a week lost …

The same thing happened with “Realistic rendering” the project of the marketplace. I had to reinstall.
my hardware is:

  • dell Intel(R) Core i7-2600 CPU @ 3.40GHz
  • 16 GB of RAM
  • NVIDIA Geforce GTS 450

A little more info might help. Such as did you crash when loading the project, on compiling, etc? Also, what kind of work were you doing the last time you were working in the editor?

Don’t know what the code means, but if you crash you should go to your autosaves work your way back until you don’t crash anymore.

Ok, I solved.
I had accidentally overwritten the Minimal_Default.umpa file with my Map.

But I do not understand why UE4 crashing when I tried open Realistic rendering of market place.
It’s strange.