How to attone.lightning.force?

I am struggling on how to expose lightning apps in force.com sites

As per one of the answers in this link I should be able to expose lightning apps on force.com sites :

Expose Lightning .app publicly?

I get a 500 error when the site accesses the lightning app. The same app renders fine on the visualforce page. What am I missing here? Is it even possible to expose a lightning app through a public site without authentication?

Lightning App:

        

VF Page used in force.com site:
 


[removed]
    $Lightning.use("c:Lightningappforsite", function() {
      $Lightning.createComponent("c:caseSearchcomponent",
      "",
      "lightning",
      function(cmp) {
        // do some stuff
      });
    });
[removed]

Output of component inside the VF Page:

Looking further in the console I see invalid session, looks like salesforce is expecting authentication to access the lightning component.

Console shows invalid session when i try to look at the raw request:

while(1); {"defaultHandler":"function(token) {try{$A.clientService.invalidSession(token);}catch(e){[removed].reload(true);}}","event":{"descriptor":"markup://aura:invalidSession","attributes":{"values":{}},"eventDef":{"descriptor":"markup://aura:invalidSession","type":"APPLICATION","xs":"I","superDef":{"descriptor":"markup://aura:applicationEvent"},"attributes":{"newToken":{"name":"newToken","type":"aura://String","xs":"I"}}}},"exceptionEvent":true}