I get the following error when executing a JSP compiled page in JBoss AS 5.0.1 (never got in JBoss 4.x) :

java.lang.NullPointerException
at org.apache.jsp.WEB_002dINF.jsp.wapp.home_jsp._jspService(home_jsp.java:1261)

here is the corresponding line code of the compiled JSP:

1261 _jsp_instancemanager.newInstance(_jspx_th_spagobiwa_005fuserMenu_005f0);

So I guess the _jsp_instancemanager is null. As far as I can get it should have been created in the _jspInit method of the servlet by the statement:

_jsp_instancemanager = org.apache.jasper.runtime.InstanceManagerFactory.getInstanceManager(getServletConfig());

So probably the problem comes from there.

Any configuration missing or something like that ?