To find the beginning of the morph, with the name, just put your cursor on the offending line and search backwards for { or for deltas, then scroll up a few lines to get to the name. I was assuming it was something about the morph, thanks for confirming it - it's probably worth making a bug report, citing examples, in the hope that the code can be tweaked to recover as Poser apparently does or at least to fail more gracefully.