It happends when u try to edit scenario:
Error while running event Fill4Me::on_configuration_changed
Fill4Me/stdlib/event/event.lua:156: Invalid player specification (player doesn't exist).
stack traceback:
[C]: in function 'error'
Fill4Me/stdlib/event/event.lua:156: in function 'dispatch'
Fill4Me/stdlib/event/event.lua:52: in function <Fill4Me/stdlib/event/event.lua:49>