How are you triggering it?
Stage > compositionReady event handler should work fine.
Also make sure that your 'source.json' file is located in the root of the project folder.
Hey Darrell, thanks for your reply!
What do mean with "triggering" ? My Testcase is just the code from my first post. Do i have to call it in an extra way or something?
Where does your code exist within your project file?
Pretty much all scripted items must be handled by some event. Since you are getting external data, the best event handler is within the Stage > compositonReady.
Is this where you have it?
yes that's the place where my code is in ...
I've found the solution ... My json file does have a syntax error and it seems to be that edge cannot load it, when it's not validated. (Of course there is no sign of an error at the dev-console or so .... )
So if anyone has the same problem - check your json file, twice!
Glad you got it sorted.