I see you are using the BETA 1.3.5 version. Since I haven't tried it (I'm on the stable 1.2.9 official current release) so I don't know it's quirks.
However, that being said I see you are making a few key mistakes: 1. You are using a 1.3 release but specifying the wrong dtd. This might cause problems. See your doctype mentioned 1_0 not, as I'm expecting 1_3: <!DOCTYPE struts-config PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 1.0//EN" "http://jakarta.apache.org/struts/dtds/struts-config_1_0.dtd"> Should be: <!DOCTYPE struts-config PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 1.3//EN" "http://struts.apache.org/dtds/struts-config_1_3.dtd"> 2. If you had the 1_0 above as your doctype, you are clearly using OLD information be it an online article, tutorial, or actual "book." I strongly recommend you look for updated documentation since some methods used in v1.0 are no longer available, i.e. deprecated and probably removed from the code by now (the 1.3.5 beta you are using). 3. Since your error message mentioned the word "modules" you should check the 1.3.5 documentation to see if you are accidentally adding a module to your config when you don't need that additional level of complexity when trying to learn Struts. 4. As you mentioned having WEB-INF/lib/app/RegisterForm.class and WEB-INF/lib/app/RegisterAction.class, I doubt classloading would be the problem, unless you are potentially using the BEA WebLogic(?) server. 5. I did not understand your answer about the form "action" attribute: did you get those error messages about the module being null from leaving the html:form action="register.do" (<-- invalid use) or by setting it to match the action's path attribute from struts-config.xml which in this case would probably be html:form action="/register" ? Regards, David -----Original Message----- From: David Fonseca Sánchez [mailto:[EMAIL PROTECTED] Sent: Wednesday, September 13, 2006 2:03 PM To: Struts Users Mailing List Subject: Re: tag library The error apears when I access to jsp page where I have the form. In WEB-INF\lib I have the package app (RegisterForm.class and RegisterAction.class), servlet-2_3-fcs-classfiles.zip, struts-taglib-1.3.5.jar and struts-core-1.3.5.jar --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]