Comment by wizzwizz4

The first and southwest-most sphinxes of seed 0 never load, which soft-locks the game. (Fortunately it doesn't corrupt the save-file.)

Edit: after fighting enough other sphinxes, the first one loads, but the west-most fails with an explicit error message:

> This challenge failed to load. Retreating.

On the next floor, the sphinx over the exit stairs fails, preventing me from progressing.