The make and model number of the projector might help.
The output of the BD player may be higher than the resolution of the projector. Check the native resolution of the projector. Connect the player to a TV and set it manually to that resolution and then try it on the projector.
The cable between the player and projector may not work in that particular combination. Try a different cable. Longer cables can be more of a problem so try a short one even if that isn't practical long term.
Sometimes the order you turn things on makes a difference. Try reversing the order.