When updating to 3.700, it displays an unknown error.
I had the same issue; I installed it manually on top of the old version.
Added 1 minute ago
I don't know if it's an HD mod glitch or my computer, but if I don't minimize Heroes and open any website or folder, I get something like this:
http://screeny.ru/53215953e8dbf8bc3806cf97
And I wanted to view daily saves, but my password keeps changing to some hieroglyphs, which is very inconvenient.
http://screeny.ru/53215b23e8dbf8bc3806d007
As for the flickering, try playing around with the color mode in the launcher.
I have 32-bit GDI and 32-bit True Color, and they work perfectly.
P.S. Yes, I also see hieroglyphs with the password.
