Operating system: Windows
Graphics card: NVIDIA GEFORCE GTX 1080
(example: 2.79b release)
(example: 2.80, edbf15d3c044, blender2.8, 2018-11-28, as found on the splash screen)
Short description of error
I click on the timeline but I can't change the frame.
Exact steps for others to reproduce the error
Based on the default startup or an attached .blend file (as simple as possible).