JIRA Agile still Disabled after the Installation
Symptoms
After you had placed the plugin jar file into the installation directory and restarted JIRA, the JIRA Agile plugin is not enabled. The following stacktrace appears in the log file or System Info:
2009-10-08 22:43:47,438 main ERROR [atlassian.plugin.parsers.XmlDescriptorParser] There were problems loading the module 'rest' in plugin 'GreenHopper'. The module has been disabled.
2009-10-08 22:43:47,440 main ERROR [atlassian.plugin.parsers.XmlDescriptorParser] Cannot find ModuleDescriptor class for plugin of type 'rest'.
com.atlassian.plugin.PluginParseException: Cannot find ModuleDescriptor class for plugin of type 'rest'.
The following plugins failed to load:
GreenHopper: OSGi plugins cannot be deployed via the classpath, which is usually WEB-INF/lib.
URL is: jar:file:/C:/Program%20Files/Atlassian/JIRA%204.0.1/atlassian-jira/WEB-INF/lib/jira-greenhopper-plugin-4.2.1-jira40.jar!/atlassian-plugin.xml
Cause
You had installed the plugin jar file into the wrong directory.
Resolution
For JIRA 4.x onwards, you need to put the jar file into <JIRA_HOME>/plugins/installed-plugins directory. You can refer to the GreenHopper Installation and Upgrade Guide documentation as a guideline to install/upgrade the plugin.