# Manual talk:Troubleshooting math display errors

The following discussion has been transferred from Meta-Wiki.
Any user names refer to users of that site, who are not necessarily users of MediaWiki.org (even if they share the same username).

math does not work if safe_mode is enabled. this is because math.php uses backticks, which is unsafe. someone needs to make a math.php which can run in safe_mode. --207.109.251.117 05:01, 3 November 2005 (UTC)

Can anybody help me? My MediaWiki install creates perfect png images in math/tmp but these are never shown in the browser. The error messages returned are below. I am not running in safe_mode. Many thanks, [[Joejk2 13:40, 29 April 2006 (UTC)]]

My solution to this problem was simple - upgrade to MediaWiki-1.6.3. Bonza! [[Joejk2 14:47, 29 April 2006 (UTC)]]

Still having problems....

Can anybody please suggest why certain symbols fail to render correctly in my install. Something like

${\displaystyle P(r)\alpha r^{n-1}\exp(-kr^{2}/2\sigma ^{2})}$

renders beautifully whereas replacing the \alpha with a \propto causes the whole equation to be shown without rendering as
P(r) \propto r^{n-1} \exp(-kr^2/2\sigma^2)

Certain other symbols also don't work e.g. \nabla and \sim. The strange thing is that perfect png images are created in my images/math folder - just for some reason they are not correctly displayed.

Joejk2 18:55, 3 May 2006 (UTC)

The reason the above works is that it doesn't have to make a png to lay it out (it's all html). I think you should make sure your latex, dvips, convert are working. m:Help talk:Running MediaWiki on Mac OS X this link shows you how to do that in the OS X section. Basiclaly, execute

Check that you got something that worked using a command line like

./texvc '/Library/WebServer/Documents/wiki99/images/tmp' '/Library/WebServer/Documents/wiki99/images/math' '\int_{-N}^{N} e^x\, dx' 'utf-8'


(As before, replace the two wiki99/images paths with the math and tmp paths we just created above. Assuming this worked, we should get a cryptic line of output,

 This is dvips(k) 5.95a Copyright 2005 Radical Eye Software (www.radicaleye.com)
' TeX output 2005.07.23:0928' ->
<tex.pro><texps.pro>. <cmmi12.pfb><cmsy8.pfb><cmmi8.pfb><cmex10.pfb>[1]
l4e053ca66cfc79a2397c40aa34c66a25<table><tr align='center' valign='bottom'><td><i>N</i></td>
<td></td></tr><tr align='center'><td><font size='+2'>∫</font></td><td><i>e</i><sup><i>x</i>
</sup> <i>d</i><i>x</i></td></tr><tr align='center' valign='top'><td> − <i>N</i></td><td></td></tr></table>1


Also look in the images/math directory where there should be a *.png file. (If something went wrong in the conversion to a png, there will also be a *.tex file in images/tmp.) Toss the *.png and *.tex files now. 70.17.83.29 19:05, 4 November 2006 (UTC)

## Failed to parse (Can't write to or create math output directory)

I got this error when I enabled wgUseTeX after $wgMathPath etc. Did you check for permissions/ownership of the director(ies)? -- Kowey 07:20, 9 August 2006 (UTC) I'm having a similar problem. Here is the issue. The directories are relative to my webroot, so the file is located at ~/Sites/wiki/up_loads/ et cetera. But the "directory" accorind to "$wgScriptPath" is "/~name/wiki". So if I set it up so that the path points to a real place on the computer, it writes the files and the browser is pointed to a relative path on my computer (bad) and if I set it up so that the path points to the web directory, the file doesn't exist on the OS and it would let it write there. Any suggestions? 70.17.83.29 19:01, 4 November 2006 (UTC)

Sorry to bother, figured this out on my own. Will post result over at m:Running MediaWiki on Mac OS X 70.17.83.29 19:38, 4 November 2006 (UTC)

## Failed to parse (Unknown error)

What helped me was a recompilation of the ocaml stuff via

 cd /var/www/mediawiki/mywiki/math
make clean
make


Good luck --Sigbert 17:33, 18 September 2009 (UTC)

## Stupid failure reasons

I'm not sure where to mention it, but texvc was failing for me because /dev/null was not writable by Apache on the default permissions for Fedora 12. Dragons flight 01:40, 23 May 2010 (UTC)

## can't get it to work

I have a problem with my latex working. It looks like the path is all right, it would be nice to know where it calls latex (I assume in Math.php, but I'd like to know what command it is issuing...). Anybody know this? 68.239.105.234 02:31, 1 October 2010 (UTC)

## Solution for Windows 7 with XAMPP 1.7.4 and Mediawiki 1.16.2

First, my english is not good :)

Solution for "Failed to parse (PNG conversion failed; check for correct installation of latex, dvips, gs, and convert)" in Windows 7.

The render.ml in the folder wiki/math/ is optimized for unix systems. For windows systems you have to change "/dev/null" in "NUL". Then compile the texvc.exe.

If this don´t work, look into your system path and may be sure, that latex.exe, dvips.exe, converter.exe, can be found.

How to set your system path -> http://geekswithblogs.net/renso/archive/2009/10/21/how-to-set-the-windows-path-in-windows-7.aspx

Author of this: Ismet