From the JIRA knowledge base:
Symptoms
Workflow actions may be inaccessible
- JIRA may throw exceptions on screen
- One or both of the following conditions may exist:
The following appears in the atlassian-jira.log:
2007-12-06 10:55:05,327 http-8080-Processor20 ERROR [500ErrorPage] Exception caught in500 page Unable to compile class for JSP org.apache.jasper.JasperException: Unable to compile class for JSP at org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:572) at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:305)
_
Cause:
The Tomcat container caches .java and .class files generated by the JSP parser they are used by the web application. Sometimes these get corrupted or cannot be found. This may occur after a patch or upgrade that contains modifications to JSPs.
Resolution
1.Delete the contents of the /work folder if using standalone JIRA or /work if using EAR/WAR installation . 2. Verify the user running the JIRA application process has Read/Write permission to the /work directory. 3. Restart the JIRA application container to rebuild the files.