Hello,
This happens to me a lot im in the (latest) version and have this Bug.
Link cant nether to Imgur link because i cant upload Pictures. 
First Fail (develop-2494 (x64)stonehearth/services/server/town/town.luac:54: attempt to index field ‘_task_groups’ (a nil value)stack traceback:
[C]: ?
stonehearth/services/server/town/town.luac:54: in function 'create_task_for_group’
stonehearth/ai/observers/fill_storage_observer.luac:18: in function '_create_worker_task’
stonehearth/ai/observers/fill_storage_observer.luac:12: in function '_update_worker_task’
stonehearth/ai/observers/fill_storage_observer.luac:4: in function <stonehearth/ai/observers/fill_storage_observer.luac:3>)
Second Fail (develop-2494 (x64)c++ exception: lua runtime errorstack traceback:)
and both come 2 Times so its 2x the First and 2x the Second
regards Nik