Eclipse “cannot find the tag library descriptor”

[From http://stackoverflow.com/questions/1265309/eclipse-cannot-find-the-tag-library-descriptor]

In Eclipse Helios "Java EE Module Dependencies" in the project properties has been replaced with "Deployment Assembly".

So for solving this problem with Eclipse Helios, the way I did it is the following:

   

• Right click on the project in package explorer and choose "Import..."
•     Accept the default selection "File System" and press "Next"
•     Press "Browse" in the From directory line, go to your tomcat installation and locate the file webapps/examples/WEB-INF/lib (I have tomcat 6, other versions of Tomcat may have the path webapps/jsp-examples/WEB-INF/lib). Once in the path press OK.
•     Click besides jstl.jar and standard.jar to activate the check boxes
•     On the line Into folder click on Browse and choose the library folder. I use /lib inside the project.
•     Click "Finish"
•     Right click on the project in Package Explorer view and choose properties (or press Alt + Enter)
•     Click on "Java Build Path"
•     Click "Add Jar", click on your project, folder lib, select jstl.jar, press OK
•     Click "Add Jar", click on your project, folder lib, select standard.jar, press OK
•     Press OK to dismiss the properties dialog
•     Click on the Problems view and select the message "Classpath entry .../jstl.jar will not be exported or published. Runtime ClassNotFoundExceptions may result.".
•     Right click on it and select "Quick Fix".
•     Accept the default "Mark the associated raw classpath entry as a publish/export dependency" and press Finish.
•     Do the same for standard.jar

This solves the problem, but if you want to check what has happened in "Deployment Assembly", open the project properties again, select "Deployment Assembly" and you'll see that standard.jar and jstl.jar have been added to WEB-INF/lib folder.