always save the game during a Magma Golem skirmish as soon as you can because there is a common bug in LOGII  custom dungeons using Magma Golems 1 level down from the party
this is how the bug occurs

Magma Golems strike out at the party who are positioned 1 level up and looking down into a basin where a magma Golem is
there causes the game to crash

HOW TO AVOID THE BUG
situate the party away from the edge of the basin at all times , ensure you SAVED THE GAME on first arrival in THE MINE

don't stand the party at the edge of a basin so that a Magma Golem strikes out at the party from below, this crashes the game