This has been an issue since day one for me, and it seems at least a few other people have the issue according to my many, many searches on the issue.

Once a day (about), I'll be completely unable to start recording high-framerate videos. When I try to select 120 frames per second in the camera app, I get a black screen for a second and then it crashes out of the app.

Oddly, when I'm having the issue with the camera, I'm also unable to play any Youtube videos in the actual Youtube app without getting a "There was a problem while playing" screen - no matter what I do, nothing will fix the issue aside from a restart. I can watch them via the overlay inside of other apps (Reddit Sync, for example), but nothing I do will load them within Youtube.

It seems to be mostly random (I have a hard time actually triggering the issue), but tends to manifest itself first thing in the morning - after sitting idle for some time overnight.

I've already tried everything that I can think of to resolve the problem - wiped my cache, wiped the data of the Youtube and Camera apps, "rolled back" to older versions and re-upgraded, upgraded to 6.0.1 (it also happens on 6.0, by the way), and I've also performed a complete wipe/reinstall of all of my applications and data. Nothing has worked.

You can see a screenshot of the "there was a problem while playing" screen here, not like it'll help much with diagnosis, but no matter how many times I tap "retry", I can't get past it without rebooting my phone completely.

Android on my phone is completely stock with no modifications aside from an unlocked boot loader.

I'm keeping an eye on the issue at the moment, but since it's so random, I haven't got a logcat of the actual failure. I'll get one of the camera crashing and Youtube failing when it happens to me again, though, and I'll update my post accordingly.

TL:DR (I've made a wall of text and I apologize for that): I'm randomly unable to play Youtube or record 120/240 fps video on my stock 6p. Reboot "fixes" it temporarily. I've tried a full wipe and the upgrade to 6.0.1 to no avail.

Edit: I've made a bug report - check it out here and star it if you're also having the issue: https://code.google.com/p/android/issues/detail?id=196966