Version: 0.2.10
Platform: Linux (very messed up)

I get a Segmentation Fault in the level editor as follows:

1. Edit a new room.
2. Set the floor to NONE or VOID
3. Place a block for the player to stand on such that it is at least 1 voxel above the bottom.
4. Align player above said block.
   (prior three steps are to prevent player from flying up out of the room of falling down out)
5. Enable extended walls feature (check box in EDITING ROOM box.
6. Set the associated Z value to some value above 63.
7. Start the play test of the room.
8. Shoot.

If the value is set > 63, it seems it is clamped to 63 (the bottom of the room) for movement collision detection, but bullet collision detection does not seem to be protected and crashes immediately.

Now, why was I setting it to 127 instead of 63? Wetware bug, of course. :P

Edit: Fixed in 0.2.11

Thanks for the report, will fix for 0.2.11