Hello,
I'm experiencing this issue, as shown on this Youtube video:
It happened two times on my iMac
Model is iMac Retina 5K Late 2015 with R9 M395X graphics.
I didn't upgrade RAM (if someone asks) but I'm waiting for 16 GB upgrade kit (iMac 5K certified).
Thanks
EDIT: I'm using macOS Sierra 10.12.1
I'm experiencing this issue, as shown on this Youtube video:
It happened two times on my iMac
Model is iMac Retina 5K Late 2015 with R9 M395X graphics.
I didn't upgrade RAM (if someone asks) but I'm waiting for 16 GB upgrade kit (iMac 5K certified).
Thanks
EDIT: I'm using macOS Sierra 10.12.1