System Information
Operating system: Windows 10
Graphics card: Intel® HD Graphics 620 (Kaby Lake GT2)
Processor: Intel® Core™ i3-7020U CPU @ 2.30GHz × 4 (64-bit)
Memory: 8 GB

Blender Version
Blender 2.80 RC2

Short description of error
Trying to paint a simple texture with image paint and unaltered texture paint tab. Using "look dev" mode for viewport. I setup a mask and texture and it allows me to edit my texture in texture paint and viewport for a while then it crashes.

Exact steps for others to reproduce the error
Paint for a while with image textures and image masks. Your mileage may vary.