You should turn on devMode
on via setting a constant in the struts.xml
. This mode is used if you want to troubleshot some issues like yours. It's more informative because it outputs to the console errors that are hidden in the normal mode.
<constant name="struts.devMode" value="true" />
After turning it on you may discover that you have wrong or inconsistent library set deployed with your application. You might find a java.lang.NoClassDefFoundError: org/apache/commons/lang3/StringUtils
printed to the console, then adjust your library set with missing jars.
The commons-lang3-3.1.jar
is required to resolve error.