Null Pointer Exception, Tomcat/Java error or Blank Page

Symptom: you start the Desktop Manager but only a blank page or error messages appear.

Possible causes: if the error mentions NoClassDefFoundError: sun/tools/javac/Main, then the Java Web Console is using the wrong Java version.

Solution: the current Java Web Console Java environment can be checked by executing # smreg list -p and looking at the java.home property. This property must point to a valid Java home, and that home must be a JDK. If this value is incorrectly set, you need to execute the following command:

# smreg add -p java.home=<JAVA_HOME>

<JAVA_HOME> must point to a valid installation, for example, where javac can be found in the bin subdirectory.

You then need to restart the Java Web Console with the following command:

# smcwebserver restart