unable to instantiate tag f:view

Im using JSF1.2 and when i use the <f:view> tag in the jsf page, i got the above error.

i have all the required libraries(jsf-api.jar,jsf-impl.jar) in the web-inf\lib.

What causes the error??

The complete error message and the stacktrace please.

there is no stacktrace.

Im using Jdeveloper. When i type in the tag <f:view> it show an error saying " Unable to instantiate tag: f:view (class: null) Make sure that the tag class is available and that the tag library containing the class is not excluded from this application."

So this is a problem of JDeveloper and not of JSF?

If you are using Facelets, make sure that you have

If you are using JSP, make sure that you have

at the top.

ya, i have the 2 lines on top
<%@ taglib uri="http://java.sun.com/jsf/html" prefix="h" %>
<%@ taglib uri="http://java.sun.com/jsf/core" prefix="f" %>