JSPs are no longer supported. Plain JSPs can still be used but JSP taglibs can no longer be loaded from Freemarker templates. Note that taglib URIs in JSPs and jinc files must be adjusted to the Jakarta Taglib URIs. http://java.sun.com/jsp/jstl/ must be replaced with jakarta.tags, for example. See https://jakarta.ee/specifications/tags/3.0/jakarta-tags-spec-3.0#multiple-tag-libraries and https://jakarta.ee/specifications/tags/3.0/tagdocs/index.html for further information