MCEdit not working.

Make sure MCEdit uses your best graphics card if you have more than one. For instance, if you have a laptop with a weak integrated card and a more powerful nVidia card, open the NVIDIA Control Panel, go to "3D Settings" -> "Manage 3D Settings" -> "Program Settings", click "Add", browse to and select your mcedit.exe, then set the preferred graphics processor to "High-performance NVIDIA processor". Click "Apply", close NVIDIA Control Panel, and you're done. Worked for me, at least .

I have the exact same problem. Whenever I open a world in MCEdit, I can see all of the gui but not the world. The world does flicker into view briefly when I rotate the camera, and I can select an area of blocks and see their silhouettes. It does the same thing whether I use 32 and 64 bit.

I hope that's specific enough.

I downloaded it twice already, one was 32 bit and the oher was 64 bit both did the same. The screen is pretty much all black but it flickers the world every now and then.

Could you be more specific? You might want to go to mcedit.net and report your issue there. I suppose you could try and download MCEdit again, that might fix your issue.