OpenCms won't start!
There are a number of things that can make your OpenCms installation break, if it was previously running.
The most useful thing you can do is turn on extra debugging information in the log. Then the log will usually give you enough clues to fix it.
To do this you would look in the file: %tomcat directory%\webapps\ROOT\WEB-INF\classes\log4j.properties
Find the line:
Change it to:
Don't forget to change it back once you've solved the problem, or the extra logging could create performance problems.
Mangled XML files
If you edit the XML file manually, and make a mistake, this will cause OpenCms to not start and give you unhappy critical errors. Usually if you look in the opencms.log you will see something about SAX parsing errors.
ALWAYS BACKUP YOUR CONFIG FILES BEFORE EDITING!!!
You will need to fix the XML problems before it will start again, this is easiest done by restoring the old file.
Missing Scheduled Job Class
If you delete or rename a jar file or class file, that is used in a Scheduled Job, this can make OpenCms refuse to start.
You will need to restore the class or jar file that contains the Scheduled Job.
If you can't do that quickly, and you really need to get your server up, you can edit (after backing up) opencms-system.xml and remove the offending job.