Problem running the sample gadgets

[Erel Segal]

I try to run the sample gadgets in javascript/samplecontainer/examples, e.g.

http://localhost/shindig/php/gadgets/ifr?url=http://localhost/shindig/php/gadgets/files/samplecontainer/examples/SocialHelloWorld.xml&nocache=1&container=container07

(shindig/php/ is my web_prefix, and container07 is a configuration file
where I changed all the paths to match this setting.

I get the following Javascript error:

data.get("viewer") has no properties
render(Object responseItems_=Object globalError_=true)ifr (line 312)
sendResponse(Object responses=false error=badRequest)ifr (line 151)
processNonProxiedResponse("/shindig/php/social/data", function(),
ObjectCONTENT_TYPE=
JSON METHOD=POST AUTHORIZATION=SIGNED, XMLHttpRequest)ifr (line 84)
makeClosure()ifr (line 23)
var viewer = data.get('viewer').getData();

I get the same error on all three gadgets in that folder.

Can you please tell me what I am doing wrong?