I was changing settings in EvoGUIs (https://mods.factorio.com/mod/EvoGUI) dropdown settings ui when ACT caused a fatal crash, log paste:

1820.227 Error MainLoop.cpp:1202: Exception at tick 73199: The mod Actual Craft Time (0.4.8) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event Actual_Craft_Time::on_gui_checked_state_changed (ID 3)
Only checkbox and radiobutton gui elements contains state property.
stack traceback:
Actual_Craft_Time/control.lua:494: in function 'toggleRadio'
Actual_Craft_Time/control.lua:744: in function <Actual_Craft_Time/control.lua:733>
stack traceback:
[C]: in function 'index'
__Actual_Craft_Time/control.lua:494: in function 'toggleRadio'
Actual_Craft_Time/control.lua:744: in function <Actual_Craft_Time/control.lua:733>

Thanks for the report. EvoGui was activating ACT code by mistake due to the weak checks I had in place. I've made a fix and added further checks so this shouldn't happen again.

Thanks muchly :D