Most of the time, when players complain about the "bug" where the screen is black with only the minimap showing where you are, you can fix it with the following small procedure.
what you see is possibly like the following picture
[Linked Image]

to fix this, double click on either your hero or deathknight's portrait as shown below
[Linked Image]

after that, your screen should be back to normal
[Linked Image]

This solved most of the "black screen bug" problems i have encountered.

Your existence alone, is excuse enough for the creation of the entire universe… Il you my darling Jeanne-Dré 