Well, on some levels this message is printed on my console, probably indicating
that too many dead/hacked bots to be respawned are present:
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FreedroidRPG 0.15-1281-gec9895a_mod encountered a problem in function:
teleport_to_random_waypoint
There was no free waypoint found on level 53 to place another random bot.

The problem mentioned above is not fatal, we continue the execution.
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This did not happen on level 59, however, probably because you cannot easily
place too many robots there. You could possibly leave them hacked and alive,
causing a respawn as hostiles while Tux is absent. When killing them, the "too
many obstacles" problem occurs first. Perhaps I should invisibly run around,
triggering more teleportations, and see what happens.

Living robots obviously don't count as obstacles.

When you level up, you can make your way even through an already overcrowded
level, but if you don't actively avoid it, you can hit this obstacle problem.

This should simply be made non-fatal, I think. The message printed indicates
that it is already intended as non-fatal, but in fact it is not, and leads
unevitably to a crash.