Hi all,
I experience the very same issue as many of others here on my production 15inchs MBPr mid-2014 (16Go, intel Iris Pro) and I think I found very interesting things.
Base symptom encountered :
since the 10.11.4 upgrade, the machine will crash randomly (black screen, fan going at full speed) sometimes some graphic glitch in the seconds before the blackscreen. The MBPr will crash especially when dealing with safari/firefox and videos, but also with other apps.
I tried all the stuff on the internet (PRAM, SMC, cmd+r reinstallation). The only things I didn't do : completely erase and reinstall or restoring from a backup prior to 10.11.4.
I'm persuaded like many of you that it's a software update related problem (between 10.11.3 and 10.11.4). I don't think the update is itself buggy, I think that during the installation process of the update, something was messed up on given systems.
I also own a second retina (mid-2012 intel HD4000 + Nvidia GT650m) which doesn't encounter the problem
Both machines are now under Sierra 10.12.1. (mid 2014 crashing and mid 2012 not)
My diagnosis (until now) :
- booting mid2014 rMBP on mid2012 rMBP (through thunderbolt cable) -> problem disappears
- booting mid2012 rMBP on mid2014 rMBP -> problem disappears
and last but not least :
I found a workaround now to avoid the crashing machine to crash. (hopefully also functional by you) : disable airport
When using the problematic machine with a Thunderbolt Display (using the network through the monitor's ethernet) AND WiFi DISABLED (not just disabled after the system has already used it, disabled from boot. If it's not the case, disable WiFi and reboot the machine).
In these conditions, I'm not able to recreate the problem. I mean I can open many applications and browser tabs, having more youtube videos running in more browser, and put the machine in sleep and wake it more times with all the stuff opened. (which was a no go before, if the machine wouldn't have crashed until yet, it would have crashed during the sleep process).
If I make the same through wireless, the machine will crash in the five minutes.
I already checksumed the airport kext in both machine to ensure they were the same, they are. But the airport hardware are not the same in the 2 machines (brcm4360 in the crashing one).
Hope this helps and cheers from Switzerland