I am having the same kind of problem. And I got the ERROR MSG "Failed to parse (PNG conversion failed; check for correct installation of latex and dvipng (or dvips + gs + convert))"
But I got the same configuration works in Test environment. Still I got the error Please suggest.
I have followed below steps with no success.
* Updated packages installed
ls -lH `which gs` `which latex` `which dvips` `which convert` `which dvipng` `which texvc`
-rwxr-xr-x. 1 root root 16240 Feb 27 2015 /usr/bin/convert
-rwxr-xr-x. 1 root root 107728 Apr 27 2010 /usr/bin/dvipng
-rwxr-xr-x. 1 root root 208000 Aug 28 19:10 /usr/bin/dvips
-rwxr-xr-x. 1 root root 19104 Feb 20 2015 /usr/bin/gs
-rwxr-xr-x. 1 root root 666360 Aug 28 19:10 /usr/bin/latex
-rwxrwxrwx. 1 apache wikiadm 635300 Feb 2 16:36 /usr/bin/texvc
* applied full access (777) to Tmp,math under /Imaages directory
* Added below props inside extensions.d/math.php
$wgUseTeX = true;
$wgTexvc = "/usr/bin/texvc";
$wgLatexCommand = "/usr/bin/latex";
$wgImageMagickConvertCommand = "/usr/bin/convert";
* Increased Shell Memory at LocalSettings : $wgMaxShellMemory = 524288; which seems to be enough to render PNG.
* Allowed unlimited (cpu time, virtual memory,filesize)
# ulimit -t $1 -v $2 -f $3
But the error seems more appropriate for installing texvc. Please let me know how to re-install for same.
Thanks in Adv,