In TYPO3 6.1, how to debug why CType is not rendering at all

Question

In one of my TYPO3 6.1 sites, when I insert a content element of the CType "menu" ("Menü/Sitemap"), this is simply not rendered in the frontend. If I choose another CType, the item is output.

I have checked in the TSOB, tt_content.menu is there (css_styled_content is included).

Also, it is in the right column which is rendered via csc.

temp.maincontent < styles.content.get
temp.maincontent {
  select.where = colPos = 0
  wrap = <div class="maintext">|</div>
  // required = 1
}

How could I debug this?

Answer 1

There was a weird issue with multiple backend layouts, being rendered in various parts of the PAGE COA. I've solved it by avoiding multiple use of the same temp. object, defining one temp.homecontent and one temp.standardcontent so they are not conflicting anymore.

To answer my own question "how to debug this": Well, by debugging.

I disabled all my TS includes and created the most basic kind of site: page = PAGE and page.10 < styles.content.get. With this setup, the CType menu was appearing. So I tried continuing by adding each TS template and then, when it stopped working, by adding / removing temp.item by tempitem from the corresponding template. Until I found the conflicting part. Fairly basic. But as there were no errors or similar hints in TSOB, probably the only way.