Problem – Last week we had hard time with this problem. Our Web App was running all fine on Tomcat 5. But when we deployed our application on JRun we got
Exception parsing the TLD null : The tag function on line 14 is not a valid TLD element
Solution: – Carefully look into the Jars you are using in the classpath. In the most probability some of the Jars have some tlds which are incompatible with the JRun expects. Try removing all the Jars and carefully add only the required Jars checking the compatibility of the Jars one by one. See the explanation section below for the more details.
Explanation:- The error itself says that there is some TLD parsing error. The tag which JRun is trying to parse is having a different TLD than Jrun expects. If you look into Jrun.jar you will find a file called JSP.tld. It says tld version as 1.2. In our case we were having standard-1.1.2.jar in our classpath. That was the root cause of the problem. In fact this jar was not required at all. It was just sitting there in one of the common Jar repository. This solved our problem. You can think of looking into the struts.jar, servelet-api jars and Spring jars to check the compatibility with your JRun jars