Once you create a default context in the admin app for tomcat and commit 
changes the default context is added to the server.xml
However after a restart, the default context page is no longer accessible.

Steps to reproduce:
1) Take release and install.
2) Start tomcat.
3) Log into admin application
4) Navigate to Host (localhost)
5) In Host Actions, choose Create New Default Context
6) Make appropriate settings in New Default Context and save.
7) Commit Changes
8) Log out
9) Restart tomcat
10) Login to admin app and navigate to Host (localhost) -> Default Context
11) Error reported :
type Status report

message Error retrieving attribute debug

description The server encountered an internal error (Error retrieving 
attribute debug) that prevented it from fulfilling this request.