List members: I have a strange problem to report tonight. I will try to give as much information as possible. As part of an upgrade of a MediaWiki 1.14 installation to 1.25, I installed the Math extension on my server. This is a fully-dedicated server to which I have root and ssh access. I even made sure to place instances of every conceivably required executable in the /usr/bin directory, where any user, including system users, could access it. That includes texvc, texvccheck, and texvc-everything else, in addition to the classic LaTeX executables. I just went through the full routine to troubleshoot math rendition errors: https://www.mediawiki.org/wiki/Manual:Troubleshooting_math_display_errors#.… ls -lH `which gs` `which latex` `which dvips` `which convert` Check. ls -lH `which dvipng` Check. texvc /home/wiki/tmp /home/wiki/math "y=x+2" And here is where I start having some problems. When I create a directory called "images" in a /private/ directory (~/private), and in that directory I create the directories "math" and "tmp," and then run texvc images/tmp images/math "y=x+2" I get an output that shows the steps it took to render that math. The output ends with one of the generated tags. And when I go to the directory ~/private/images/math, there lies a new file. I download that onto my own machine, and it shows the display I expected. In fact, here it is, attached. Now: I go to public_html, or, say, public_html_ru (or any of several second-language directories for second-language versions of my wiki), and execute texvc images/tmp images/math "y=x+2" I get almost the same output as before. Almost. To the last tag, I see appended a minus sign. Then I look in the math subdirectory. NO FILE. So I tried building a new math subdirectory in a dummy images file. The texvc program executed flawlessly. Then I copied that recursively to the Russian CreationWiki images directory, and ran the texvc command again. NO FILE. And a minus sign at the end. Now I see the modern MediaWiki puts a directory called "lockdir" in the images file (but not the math directory). Why should that make any difference?!? Let me anticipate the solution some of you are going to recommend: why don't I just use "Mathoid" for all maths? Well, a funny thing happened over the weekend when I tried that. The Mathoid service had a crash. It's down. And you know what? It's still down. For everybody. I checked that out with the site "Is It Down for Everyone or Just Me." Result: "It's not just you! This site looks down from here." http://mathoid.testme.wmflabs.org%27/ Besides: my associates and I pay good money for a fully dedicated server with root and secure-shell service. We expect to be able to install LaTeX on it and to have it work consistently whenever I specify temporary and permanent math-image-storage directories that do exist. We can't understand why the executable should work sometimes, but not other times. Nor why it should quit working when all I do is copy in another directory! I've asked my associate to submit a trouble ticket with our Web hosts. I start to wonder whether I am seeing some kind of security issue that is stopping LaTeX and the texvc program from executing on any directory that "looks funny." But I thought I'd check with you guys as well, in case I'm missing something. Other data: the setenforce 0 and setenforce 1 commands both return "selinux has been disabled." Make of that what you will, but to me is looks as though our hosts didn't want to encumber us with that. (I don't know exactly what distro of Linux we're running--maybe CentOs. It's some kind of Red Hat-derived service, because it uses the "rpm" package system and "yum" to install. Both of which I know like the back of my hand. I used those to install most LaTeX executables, plus "ocaml" so I could make "texvc" and its associated applications. User "Temlakos"