I have set up a Liferay Tomcat Server in Eclipse. After the server starts and I go to localhost:8181 (where I configured the server), the page is empty. Also, if I right click the server in Eclipse and select Open Liferay Portal Home, a 404 Page Not Found is displayed.
When I start the server outside Eclipse, with startup.bat, the page loads just fine.
Does anyone have a clue about why this might happen?
This answer assumes you're using Liferay IDE in Eclipse. It might be accurate even if you're not.
Try making your edits in the Eclipse workspace's server.xml file. The workspace should have a Servers folder, with your Tomcat Liferay server underneath it. The path in my workspace is as follows:
eclipse-luna-workspace/Servers/Liferay v6.2 CE Server (Tomcat 7) at localhost-config
Underneath the directory for the server are copies of the Tomcat configuration files, including server.xml. Make your edits to this server.xml file, restart your server in Eclipse, and Eclipse should copy it to the Tomcat instance at startup.