The mod Enemy Race Manager (2.0.45) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event enemyracemanager::on_nth_tick(11)
enemyracemanager/lib/attack_group_beacon_processor.lua:937: attempt to index field '?' (a nil value)
stack traceback:
enemyracemanager/lib/attack_group_beacon_processor.lua:937: in function 'pick_spawn_location'
enemyracemanager/lib/attack_group_processor.lua:577: in function 'generate_group'
enemyracemanager/controllers/cron.lua:34: in function '?'
enemyracemanager/lib/cron_processor.lua:22: in function 'process_one_job'
enemyracemanager/lib/cron_processor.lua:155: in function <enemyracemanager/lib/cron_processor.lua:154>

This happen after a few minutes starting the game and its is similar to others... Can you help please?

Does it always happen? Do you play with other mods?

I think I'll need your save even if it happens after a few minutes of starting the game. I need to see the internal data. It happened on different area than others.

It's fixed for the upcoming release. (2.0.46)