Null Pointer Exception when clicking "Blocks with Samples"

[Frank Müller-Witte gmx]

Hi, I've moved cocoon from the Jetty-Default-Webserver to Tomcat by copying "webapp" into "webapps" (and I've renamed 'webapp' to 'cocoon' , but since then I get the error message below when I want to check out the block examples. What did I do wrong? Thanks, Frank An error has occured java.lang.NullPointerException: Cocoon stacktrace[hide] context://samples/common/style/xsl/html/simple-samples2html.xsl - 32:11 context://samples/common/style/xsl/html/simple-samples2html.xsl - 32:11 Failed to process pipeline context://samples/common/style/xsl/html/simple-samples2html.xsl - 32:11 [SAXParseException] context://samples/common/style/xsl/html/simple-samples2html.xsl - 32:11 [TransformerException] context://samples/blocks/sitemap.xmap - 53:25 <map:serialize> context://samples/blocks/sitemap.xmap - 50:94 <map:transform> context://samples/blocks/sitemap.xmap - 49:48 <map:transform> context://samples/sitemap.xmap - 201:65 <map:mount> context://sitemap.xmap - 961:66 <map:mount>