I get this error (in console) when starting Tomcat using startup.bat but NOT when starting via the windows start tomcat menu option (ie: no error in tomcat logs). I have one app deployed using struts 1.1 and have added jstl.jar and standard.jar to tomcat/common/lib directory. The app and tomcat seem to run fine despite this error. I don�t have the resource path /WEB-INF/lib/commons-collections.jar specified anywhere in the app.