HTMLDOC Problem:

Htmldoc produced no pdf-output.
/usr/bin/htmldoc --size A4 --bodyfont Arial --fontsize 13 --headfootfont Arial --headfootsize 11 --no-links -t pdf13  --webpage -f /home/www/ncf2295/html/typo3temp/hd_wOybbV - 2>/home/www/ncf2295/html/typo3temp/se_8E24go

This is the (stderr) output of the htmldoc command without the htmldoc_append parameters:
If you see no errors here please check your htmldoc_append parameters too.
HTMLDOC(5665) INFO: HTMLDOC 1.8.27 starting in CGI mode.
HTMLDOC(5665) INFO: TMPDIR is "(null)"
HTMLDOC(5665) ERR005: PATH_INFO is not set in the environment!
Can't open display: