Reload from an autosave from before the Avatar entered Erebus, then play. The Avatar of Wrath-related problems (CtD or WoC) are influenced by the random number generator, and so a different play-through may not produce the problem. If you do have to reload an autosave, I suggest making a manual save each turn until after the Avatar has been around for several turns. If another crash or endless turn happens then reload your latest save and play a game of Somnium with someone before ending your turn. This will "shake up" the random number generator, and may sidestep the problem.