Problems with the "Shades of Darkness" expansion.

Hello, maybe someone can help me with this problem: after completing the first mission in the Dark Elves campaign (Heroes 6: Shades of Darkness), the second mission, "Call of Mallassa," doesn't load. When I click "Continue" to proceed to the next campaign mission, a black screen appears, and the game doesn't progress further. I have to exit through the task manager. Has anyone encountered a similar problem? Please advise on how to resolve it. I have patched the game to version 2.1.