Operating system: Windows-10-10.0.18362 64 Bits
Graphics card: Quadro M6000/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 431.02
Broken: version: 2.81 (sub 3), branch: master, commit date: 2019-08-21 20:48, hash: rB189aa32a3ac0
Short description of error
Emulate 3 Buttons doesn't work with ALT Modifier key on UI buttons
Exact steps for others to reproduce the error
When we add modifiers keys to a button on pie menus or UI buttons, Emulate 3 Buttons doesn't work with the ALT key.
Example: This button allows several actions with modifiers keys.
ALT doesn't work with Emulate 3 Buttons.