GUI crashes – how to enable (crash) log?

The waifu2x-caffe GUI crashes with some images in a folder. Because it’s a bit messy in the start and destination folders, I can't figure out which image(s) is/are responsible. (I’d found four other images where it happens before when it was more tidy.) How can I easily find out which other image is now causing it to crash? How can I have a (crash) log created?

I would’ve tried it with command line to see if I get an error message there. However, I don’t know how to get the identical command that the GUI uses.