Redream dreamcast emulator problem

Hello to all, i have a problem,
i am trying to emulate dreamcast throught redream, but the game do not start at all. All i get is a black screen, the game starts in libretro/flycast but i want to use redream since in flycast i cannot configure my controls.
Also (if this helps) when i try to open the emulator itself from the folder of emulators in retrobat folder it starts really really slow. I mean the logo starts to make its appearance bit by bit grey at first and going to white as its in slow motion or something.
Can you please help?