Hello, we have the problem that some Images (all made the same way) are not able to create a thumbnail or something else. If I have the following line in it: ---- [[Bild:Pkt 1month-link-usage all.gif|thumb|left]]<br> --- but this works --- [[Bild:Pkt conf-reports.png|thumb|left]]<br> --- ------------------- Warning: call_user_func(imagegif) [function.call-user-func]: First argument is expected to be a valid callback in /srv/www/htdocs/gk_oracle/includes/Image.php on line 1159 Warning: Cannot modify header information - headers already sent by (output started at /srv/www/htdocs/gk_oracle/includes/Image.php:1159) in /srv/www/htdocs/gk_oracle/includes/OutputPage.php on line 421 Warning: Cannot modify header information - headers already sent by (output started at /srv/www/htdocs/gk_oracle/includes/Image.php:1159) in /srv/www/htdocs/gk_oracle/includes/OutputPage.php on line 449 Warning: Cannot modify header information - headers already sent by (output started at /srv/www/htdocs/gk_oracle/includes/Image.php:1159) in /srv/www/htdocs/gk_oracle/includes/OutputPage.php on line 450 Warning: Cannot modify header information - headers already sent by (output started at /srv/www/htdocs/gk_oracle/includes/Image.php:1159) in /srv/www/htdocs/gk_oracle/includes/OutputPage.php on line 509 ------------------- Thanks for Help Andreas Koch Service