My logos 5 continuously presents flickering black / blank windows within the overall window, alternating between complete black screen and partial ones.
Hi Iain - and welcome to the forums
Sounds like a video issue - have you checked your video card drivers are up to date?
And would be worth looking at moving to Logos 6 - version 5 is no longer supported.
You can get the free Logos 6 core engine at https://www.logos.com/install
Graham