Occurring on v0.12.0a, seems to occur when opening inventory to equip a character:
SCRIPT ERROR: Invalid call. Nonexistent function 'get_active_effects' in base 'Nil'. at: generate_data (res://src/character/ch_dyn_stats.gd:153) - Invalid call. Nonexistent function 'get_active_effects' in base 'Nil'.