User is STILL not providing detail despite me asking multiple times (grrrrr!!!!), but we have narrowed it down to the Windows 10 setting in System/Display/Scaling. If this is 100% then the dialog is fine, but on a 4K display when you need to set it to (say) 150% or 200% or 250% in order to be able to read anything, then the dialogs come out wonky.
My guess is that mIRC is enlarging the text and Windows is enlarging the text too - so we get double enlargement.
I will try setting the Windows scaling on my PC and see whether I can reproduce it.
Last edited by Protopia; 02/09/18 03:17 PM.