weblogic.management.DeploymentException: Error: Unresolved Webapp Library references for ServletContext

Problem in starting the EMConsole on Weblogic Server 10.3.3
Error in starting the Deployment comonent EM in WLS 10.3.3 Console
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@437235777[app:em module:/em path:/em spec-version:2.5]", defined in weblogic.xml
[Extension-Name: jstl, Specification-Version: 1.2, Implementation-Version: 1.2.0.1, exact-match: false],
[Extension-Name: jstl, Specification-Version: 1.2, exact-match: false]
Errors were encountered while performing this operation.
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the applications EAR had an empty lib folder, when i looked in the console to check if any jstl modules were deployed as library, i found that it was not activated.
i had the module activated and redeployed the application and it worked.
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ref:
http://download.oracle.com/docs/cd/E12840_01/wls/docs103/webapp/configurejsfandjtsl.html#wp162992