I’ve a complex script in few modules with init file etc…
I want to load one of this module on startup if a Preference Prop of the addon are compiled (like Password).
But the property are not found at startup (because it not exist I suppose).
addon_prefs.execute = True
AttributeError: 'NoneType' object has no attribute 'execute'
How do this?
Compiled ? 
Not very clear this part, could you explain a little more ?
Maybe it’s a matter of ordering module register (if they are interdependent, order matters, you must register dependencies first, otherwise it does not exist at register time)
See you 
++
Tricotou
Compiled, bad english, sorry, Fill the form where you store the property in UI.
I’ve find a workaround:
I’ve a function to show preview icon of enum menù.
If I call the module in this function it work because this function is attached on Windows Manager:
WindowManager.flared_previews = EnumProperty(
items=enum_previews_from_directory_items,
And its called one time, only when you open the Addon UI the first time.