Revived

I'm curious where that error might have come from.

First of all, it would be good to have various try-catch blocks everywhere in the code – so that no matter what happens, you can handle it and gracefully end the script (at least change the victory conditions to automatic).
I don't understand from the script where you are summoning these Hydras... Does the script determine the nearest free space near the main Hydra? I'm not sure that this will happen correctly in 100% of cases.
But otherwise, it looks normal...