Internal server error on anyonymous login

[Mshaji]

I am getting 500 Internal server error when I am not logged in to cq5. I don't even see http://localhost:4502/welcome or http://localhost:4502  page.

Only way I can login is through http://localhost:4502/crx/de/  this url works when I login as admin I can see all the pages or browse to other cq5 urls.

I am using standalone cq5 instance on localhost with no dispatcher, no cluster - version 5.6.1 on windows.

Here is the detail error.log

23.03.2015 09:26:03.024 *INFO* [0:0:0:0:0:0:0:1 [1427117163023] GET / HTTP/1.1] org.apache.sling.auth.core.impl.SlingAuthenticator getAnonymousResolver: Anonymous access not allowed by configuration - requesting credentials
23.03.2015 09:26:03.024 *INFO* [0:0:0:0:0:0:0:1 [1427117163023] GET / HTTP/1.1] servletengine Servlet threw exception:  java.lang.NullPointerException
    at com.adobe.granite.auth.saml.impl.SlingKeyProvider.getDecryptionKey(SlingKeyProvider.java:100)
    at com.adobe.granite.auth.saml.configuration.SpConfiguration.getDecryptionKey(SpConfiguration.java:79)
    at com.adobe.granite.auth.saml.SamlAuthenticationHandler.requestCredentials(SamlAuthenticationHandler.java:367)

[vijayraj_vk · Accepted solution]

Looks like SAML authentication has been enabled for the root path. If SAML was not  enabled intentionally please access  the web console  and search for SAML and disable by removing the path. This works fine when you access the crxde as the default handler is used for this.