ERROR - About EP Perspective in SAP Netweaver studio

Dear All,

Whenever I try to set the server settings for enterprise portal in Windows - > prefrences I get an error

'Unable to create the selected preference page'

Reason

Plug-in com..sap.ep.connectionManager was unable to load class com.sap.netweaver.ep.ui.preferences.PreferencePage

Due to this I am not able to upload any PAR from studio to EP.

Regards