When accessing a page that is defined with a layout template that isn't deployed, Liferay just send a NPE with poor information about it.
Perhaps it should send a clear message about the fact that the layout template isn't deployed or maybe just make a fallback to a default layouttpl.
Steps to reproduce:
With a clean tomcat bundle, do:
1) deploy a layouttpl
2) create a page with that layouttpl
3) stop liferay
4) undeploy the layouttpl
5) start liferay
6) try to access the newly created page
Liferay falls back to a default layout template or send a clear message showing that the layouttpl is missing
Liferay sends a unavailability error to user and raise an NPE exception in the logs.