Thanks for your feedback. Sorry I hadn't seen your post. The latest version 2.7 fixes a bug that had to do with having shadows turned off (among other improvements). There is a chance you were hit with this bug that resulted in a black screen. Sorry about that! Please try this new version and let me know if it helps.
If the program fails to start or crashes, it would normally leave a log file in the install directory. You can send me that file so I can track the specific problem. Thanks!