Turn on logging, then try to refresh a page with a preview fomula in it, to see what happens in the logs. Permissions checks: make sure that the apache user has the ability to execute the texvc executable, and write to the /images folder. by following the advice that the program 'setroubleshootd' gives. If the error goes away under 'setenforce 0', the underlying problem needs to be fixed by the sysadmin of the webserver, e.g. A simple way to find out if this is a problem is to temporarily switch SElinux off (using 'setenforce 0'), then to see if the error message goes away, then to re-enable SElinux (using 'setenforce 1'). TeX Live seems to require the existence of a writable directory /var/Yet another possible solution: if the webserver running MediaWiki uses SElinux for enhanced security (RedHat/Fedora systems do that by default), then it may happen that the SElinux context of a file that is read or modified when running LaTex and creating a PNG may be wrong. On most distributions there has been a transition from teTex to TeX Live. Perhaps someone can write what the proper solution to this work-around is. If you try this, please be advised file /root/.texmf-var/web2c/latex.fmt is only created when you run the texvc command above. This suggestion was found on but has worked for more than three people. Another user found it at ~/.texmf-var/web2c/ If that is not installed, latex will not render a dvi from the generated tex files and consequently no png can be rendered.ДЇor FreeBSD, the file is found at '/usr/local/share/texmf-var/web2c/latex.fmt'. In case the above example didn't work: On debian, the tetex-extra package was renamed to texlive-latex-extra. On CentOS 5, this has been reported:Д¬p /root/.texmf-var/web2c/latex.fmt $wgTmpDirectoryДЄlternatively, if you have root access, you can simply run the command which the CentOS latex packages ommitted: Where the $wgTmpDirectory might be wiki/images/tmp. From here on, we assume that you have some access to the web server, specifically that you are at the directory where you installed MediaWiki, for example:ДЇunction wfMkdirParents ( $fullDir, $mode ) /tmp' ) If none of these help, you might have to start rolling up your sleeves. Are the file permissions correct? Can your image directories, include images/math and images/tmp be written to by your webserver's user?.

Are the math formulas correct latex? Try a simple formula like 0.Do you have LaTeX, dvips, gs and convert (ImageMagick)?.Have you compiled texvc? see the math/ directory.2.6.1 Wrong collation / charset (usually utf8 vs.2.5.4 NginxВ : Use absolute path in texvc sources.2.5.3 NginxВ : Execute texvc as root with sudo.2.5 'Failed to parse (PNG conversion failed check for correct installation of latex, dvips, gs, and convert)'.2.4 'Failed to parse (Can't write to or create math output directory)'.2.3 'Failed to parse (Cannot store math image on filesystem)'.2.2 No error messages but source is displayed instead of rendered formula.

Math illustrations manual