I recently joined the site and was wondering if anyone is interested in the X-Men Total Conversion mod. It was made a while ago, 1997, from Zero Gravity Entertainment. They used to have a website, http://www.x-men.com, but that has since been absorbed by Marvel.com and there is no support from them (no surprise). I have the mod on my virtual machine, so the download is pretty easy.
I have this same error as well. The mod will run in Darkplaces though. I have also seen some say run it on an earlier version of QS or Fitzquake. Trying to find a way to make it work right with current QS though… Let me know if you figured anything out~!