System Information
Operating system: Darwin-18.7.0-x86_64-i386-64bit 64 Bits
Graphics card: AMD Radeon Pro 560 OpenGL Engine ATI Technologies Inc. 4.1 ATI-2.11.20

Blender Version
Broken: version: 2.80 (sub 75), branch: master, commit date: 2019-07-29 14:47, hash: rBf6cb5f54494e
Worked: (optional)

Short description of error
Missing icons for 'Perspective/Ortho switch', 'Toggle camera view', 'Move the view', 'Zoom in/out'

Exact steps for others to reproduce the error
There are no specific steps - the icons just disappeared (however the circle background colour stays)