Simply open a file

Hi,

This is my first attempts to script IDS. I am stuck with the simpliest command: open a file.

app.open(File(myFilePath));

It returns an error.

<IDSP:RunScriptResponse><errorNumber>1</errorNumber><errorString>open</errorString><scriptResult></scriptResult></IDSP:RunScriptResponse>

I first developed on Indesign desktop and the script just works fine. I read the IDS scripting guide so I am aware of restrictions and I think I avoided them.

Is there anything to be aware of for opening files ?

Best,

Loic