[BUG: 2020 14.3.0] Lumetri Scopes panel hangs system during playback
I've come across a frustrating bug in version 14.3.0 on my system: having the Lumetri Scopes panel open during playback causes the system to hang.
No problem if the scopes panel is not visible (ie tab hidden), and no problem if the panel is visible and video is not playing, it only happens during playback after a few seconds.
The audio continues playing, but the user interface freezes and becomes unresponsive. The mouse still moves but I can't click anything in Premiere or any other app or macOS - can't even launch the Force Quit Window. The only way to get out of it is to turn the power off and boot the computer again.
It took me about 4 hours of troubleshooting to pinpoint Lumetri Scopes as the culprit. Premiere and the computer in general had been running rock solid before 14.3.0. I first noticed it when using a custom workspace with scopes, deleted that and reset all workspaces - happens in the default Color Workspace as well. The only way to avaoid the crash is to not have Lumetri Scopes visible during playback which is not ideal when colour grading.
My project contains ProRes422 DCI 4k media which my system has no problem working with. The timeline is 4096 x 2048 2:1 Aspect, clips are set to 100% size to crop top and bottom.
The Lumteri Scopes configuration I'm using is the preset Vectorscope YUV / Parade RGB / Waveform YC (no chroma), Rec.709, Brightness Normal, Clamp Signal 8-bit
PrPro 14.3.0 (Build 38)
Metal Rendering Engine, Display Color Management OFF, Extended dynamic range monitoring OFF
macOS 10.14.6 (18G5033)
CPU: Intel i7-6700K
GPU: AMD Radeon RX Vega 64 8GB
RAM: 64GB DDR4-2400 (4x 16GB, Dual Channel)
Displays: 2x 3840x2160 [Displayport, 10-bit], 1x 2560x1600 [HDMI, 10-bit]
Audio: RME Fireface 800 [Firewire 800]
Controllers: EUCON Avid Artist, Elgato Streamdeck