Created attachment 118966 [details]
Windows System Info
When OpenGL is enabled, all the dropdown menus show first as a black for the fraction of a second before they are filled with the content.
OS: Windows 10 64-bit
Nvidia GeForce GTX 550 Ti graphic card
The attachment shows the SystemInfo of the involved computer.
It does not happen on my notebook with an Intel HD Graphic 3000 graphic chip
I can confirm this, for v18.104.22.168.
OS: Windows 7 64-bit SP1 (+all updates)
GFX: NVIDIA GeForce GTX 970
I saw the issue first with NVIDIA driver v352.xx.
Updated to driver v355.98 with no change.
still present with LO 5.03.2, Nvidia driver 359.00
This should be fixed in 5.0.4 (defaulting to non-Open-GL) - and also much improved for LibreOffice 5.1.0 RC2 (due this week). Please re-open if you can reproduce in 5.1.0 RC2.