That's one of the most annoying things about testing games. It's easy to crash the things but the real challenge is working out what causes them. Particularly if you're not lucky enough to get a crash dump for the dev team to have a look at. And it gets even worse if you can't repeat it lol.
At the end of every project you've got a load of Once Only crash bugs that have to be 'Closed As Not Seen'.
I managed to break Netflix the other day which also broke the Wii U OS too lol. Netflix crapped out on me, the TV display went black. I was forced to quit the app with the Home button but after I returned to the Wii U Menu screen the TV display was still black, no Plaza lol. Had to switch the console off and on again twice, the first time the GamePad couldn't connect to the console and the second time everything was okay.
I haven't managed to break Hyrule Warriors yet though which is surprising for me, I tend to break software pretty easily which is why I made such a good tester. Not well enough to work at the moment though and haven't been for some time, would love to get back to testing when I'm able to get back to things though. It's the only job I've done in my life that I've enjoyed doing.