At first start of Kontact it shows the "Tip of the Day" dialog, and this dialog is empty, i.e. the text of the tip is missing. Reproducible: Always
Created attachment 95214 [details] Screenshot
Kubuntu 15.10 x386 Kontact 5.0.2 I confirm this bug affects me too. I also asked a couple of other Kubuntu Users who confirmed they have the same behaviour. I tried to highlight the area where I anticipated the text would be, to check if it was a font style / colour issue. It would seem there simply is not Tip text present.
We remove all tipofdays in 5.1 it was an old technology. So I close it
Ah ha, OK Thank you.