An error has occured

org.apache.cocoon.ProcessingException: Attempted to process incomplete pipeline.
<map:serialize type="html"> - context:/file:/Volumes/data1/wd/projects/Klamath/site/prod/webapp/sitemap.xmap - 637:31

Cocoon stacktrace

Attempted to process incomplete pipeline.
context:/file:/Volumes/data1/wd/projects/Klamath/site/prod/webapp/sitemap.xmap - 637:31<map:serialize type="html">
context:/file:/Volumes/data1/wd/projects/Klamath/site/prod/webapp/sitemap.xmap - 632:41<map:transform>
context:/file:/Volumes/data1/wd/projects/Klamath/site/prod/webapp/sitemap.xmap - 631:32<map:transform type="xinclude">
context:/file:/Volumes/data1/wd/projects/Klamath/site/prod/webapp/sitemap.xmap - 630:28<map:transform type="i18n">