Hello. Im from korean devloper and I want to make a report page using JasperReport. So. I installed jaspersoft studio in eclipse.(I refered the web site - http://o7planning.org/en/10247/install-jaspersoft-studio-into-eclipse , http://o7planning.org/en/10271/jasperreport-tutorial-for-beginners) I think completely installed jasper studio.(installation process is completed.) But...Window -> Open Perspective -> Report Design is not working. and show view ->other -> Repository Explorer is not working and error. Error message is " Plug-in com.jaspersoft.studio was unable to load class com.jaspersoft.studio.repository.RepositoryView. " I reinstalled jaspersoft studio plugin in eclipse. but it is not working. Eclipse version : Eclipse Java EE IDE for Web Developers. Version: Luna Service Release 1 (4.4.1) JasperSoft studio Version : Jaspersoft Studio 6.3.0 Can you please guide me on this. Please let me know if you need more details.