The Amiga conversion of Ultima VI: The False Prophet was programmed by Abersoft and first published by Origin Systems in 1992.
The game was apparently ported from the PC version and was not properly optimised for the Amiga so is considered to be unplayable by many. While I didn’t find that to be the case in the emulator I used I did discover that the game would freeze after three or four hours of play, which is probably some kind of copy protection that hasn’t been removed from the game.
You might be able to find working versions of the Amiga port of Ultima VI if you search around, but – to be honest – you’d be better off buying and playing the original PC version from GOG.com as it is by far the best one to play.
While the music in the Amiga version is better than in the other versions, that doesn’t really make it worth playing. Especially if the game’s just going to crash on you after investing a number of hours into it.