The was solved by setting up the correct resolution. Make sure to read the tutorial on how to set up bluestacks.
I’m using BlueStacks.
1. I followed the Regedit method & changed that to 410×683.
2. “Windows scaling” – I am on Win 8. Went to display scaling & changed to smallest (100%).
3. Follow the instructions for Duelit.
4. Clicked on D.L., hovered the mouse, & pressed space.
5. Error says “Wrong resolution etc”
This happened a couple of times
Solution: Maximise BlueStacks, then start Duelit.
Worked straight away.