Mod can't override vanilla event

[junjun16]

I would like to override a vanilla event mechanism

So I created a mod with folders and copy the vanilla files there to modify them
events/galactic_community_events.txt
I added a new event with id,

country_event = {
id = galcom.101
...
}​

also a folder localisation for description

After I loaded the game, it didn't work!

For a straight forward test is
console, -> event galcom.101
event not found error!

It means my event is not loaded into the game at all!.
What should I do to override vanilla event trigger mechanism?

----updating-----
Never mind. I find the error.
How can I this post?