java.lang.NoClassDefFoundError - Openscript

i have a java project in Openscript where i am trying to add an external library (.jar file) and trying to access the classes in it.. but i keep getting this error even after adding the jar to the java build path..

I tried refreshing the project.. cleaning the project and building it again..

11:27:28,817 INFO  [EntryPoint] Started with arguments: -port 7777 -jwg \Openscript\test2\test2.jwg

11:27:28,848 INFO  [EntryPoint] Creating package and resolving assets for script file... \Openscript\test2\test2.jwg

11:27:28,965 INFO  [EntryPoint] Assets were resolved successfully. Script package created

11:27:29,017 INFO  [EntryPoint] Received StartScriptEvent

11:27:29,017 INFO  [EntryPoint] Running "test2" ...

11:27:29,071 INFO  [DeploymentLogger] creating data source for databank "testcsv". Databank usage: Advance record: by script request, Select record: sequentially, Out of records: stop script execution, Start record: 1, Seed value=0