SP.ClientContext is null or not an object in ECMAScript

when you call

function Initialize()

{

var context = SP.ClientContext.get_context();
}

Initialize();

if you have a error message "SP.ClientContext is null or not an object"

In order to avoid this error you should:

//add more this one.

SP.SOD.executeOrDelayUntilScriptLoaded(Initialize, 'SP.js');

function Initialize()

{

var context = SP.ClientContext.get_context();
}

//Initialize(); REMOVED