Filename not found

Hi friends at Epic. I’m having issues with my game.
On the Editor, I have no issues at all. However, when I build the game and play for about 5 minutes, I always get a fatal error with “filename not found” followed by some codes.

I have no idea of what I’m doing wrong, can someone enlighten me, please?

Check the following screenshot for more info.

https://dl.dropboxusercontent.com/u/2739873/capture_fatalerror.png

It seems like the issue was resolved by rebuilding the project.