RHQ Server w/ server side plugins installed.
JARfile of Mazz's simple reporting plugin (more info @ http://management-platform.blogspot.com/2009/12/rhq-server-plugins-innovation-made-easy.html)
Steps to Repro :
1. upload the simple reporting plugin
2. enable and deploy the plugin, confirm that worked
3. undeploy the plugin
4. try to upload the plugin again w/o changing any of the version information, just upload it. You should get a user friendly error
Expected Result : At step “4” user should get a friendly error message .
Actual Result : Not observed any error message while uploading copy of already undeployed plugin