There is one problem with the Tag of "<tablib>" , when creating struts web project.. The error prompt as "cvc-complex-type.2.4.a: Invalid content was found starting with element 'taglib'"
<web-app>
.....
<taglib>
<taglib-uri>/tags/struts-tiles</taglib-uri>
<taglib-location>/WEB-INF/struts-tiles.tld</taglib-location>
</taglib>
</web-app>
Solution: Surround a tag of "jsp-config" :
</web-app>
...
<jsp-config>
<taglib>
<taglib-uri>/tags/struts-tiles</taglib-uri>
<taglib-location>/WEB-INF/struts-tiles.tld</taglib-location>
</taglib>
</jsp-config>
</web-app>