In the stable build you must set up a reactor like it is in the file of reactor shown: [spoiler] -- The reactor consists of an 11x11x11 cube structure -- A cross section through the middle: -- CCCCC CCCCC -- CCCCC CCCCC -- CCSSS SSSCC -- CCSCC CCSCC -- CCSCWWWCSCC -- CCSCW#WCSCC -- CCSCW|WCSCC -- CC...