ImageCache throwing 500 internal server error I'm trying to use imagecache for the first time. (already installed by someone else. currently not serving any images)

So whenever I try to see an image modified by imagecache I have a 500 internal error. In the drupal's watchdog report log there is just an error without much description:

Failed generating an image from imagecache_sample.png using imagecache preset small_analysis.


I have no idea why, but in the apache error logs, I can't find anything...

This happens even when I try to display the imagecache sample:

http://www.radicalislam.org/sites/default/files/imagecache/small_analysis/imagecache_sample.png?1344778168=
I've just ran into this issue and i solved it by enabling the ImageAPI GD2 module and disabling the ImageAPI ImageMagick module.

There's also a number of things to check: presence of the GD library in system and in PHP config, enough PHP memory to parse the images, valid file system configuration and permissions, etc.