Hi All, Our application was running fine on Weblogic 8.1 SP2. Our application is making heavy use of class casting from Object to Timestamp. For example: Object o=new Object(); Timestamp s=(Timestamp)o; But after we upgraded our server to SP4, everywhere in application we start getting the error of "Class Cast Exception". Can somebody please explain why it is so? Why the application has suddenly stopped working on SP4 when it was running fine on Weblogic 8.1 SP2.