I setup the 'Execution Environment' as JavaSE-1.5, and this was an issue as the Java couldn't recognize to cause the 'Must Override a Superclass Method' errors. After the including, some of the errors are just gone and I found that I have two more errors. I recompiled the project first, and then checked I have all the required plugins from the complaints in the log file, and then I found that I was missing the, I guess it should have been included automatically. I have only one item: '.' in Bundle-ClassPath. This is MANIFEST.MF file Manifest-Version: 1.0Р”В«undle-SymbolicName: singleton:=trueР”В«undle-Activator: .ActivatorР”В«undle-RequiredExecutionEnvironment: J2SE-1.5 What might be wrong? Why I have this error only when I execute it as standalone? ADDED However, I'm not sure exactly what might cause this error. Referring from this post, I understand that I've got a newer version of a plug-in without its dependencies, and there is something wrong in the runtime path. : org/eclipse/swt/widgets/DisplayР”Р„t 0(Native Method)Р”Р„t (Class.java:2442) !MESSAGE Exception while activating instance of component 4.ui.

Reason: Missing Constraint: Import-Package: .util.event version='1.0.0'Р”Р„t .(AbstractBundle.java:1332)Р”Р„t .(AbstractBundle.java:1316) It works without problem when I execute the application and product in eclipse IDE, but when I export and execute it, I got this error in the log file.

Reason 6 bundle