Thumbnails and previews for PDF and EPS files display as red crosses in Internet Explorer 8 but display correctly in other browsers (e.g. Firefox 3.6).
Explanation and Fix
This can happen if ImageMagick has been compiled without LCMS support. In this case the thumbnail JPEGs for some assets use the CMYK colour model instead of RGB.
To check whether ImageMagick has LCMS support, first find out the ImageMagick directory from the imagemagick-path setting in asset-bank/WEB-INF/classes/ApplicationSettings.properties. Then substitute this for <imagemagick-path> in the commands below.
/opt/local/lib/liblcms.1.dylib (compatibility version 2.0.0, current version 2.19.0)
Should not happen on Windows if you use the precompiled version of ImageMagick (instead of compiling it yourself).
If the above commands don't produce any output then ImageMagick is not using LCMS. Make sure that you have the LCMS headers installed (e.g. install the lcms-dev or lcms-devel package on Linux) then reconfigure, recompile and reinstall ImageMagick.