I took over the website from its previous administrator (Joomla, rt_hadron template) and it was a VERY old version (1.0 from something like 2013). I needed to make some updates to other plugins and it appeared to break the existing template.
I went to recompile the LESS template and I guess it's so old that a lot of the syntax is no longer valid. I updated the template and most of the errors have been corrected but when I try and recompile global.less, I get the error that
variable @mainbody-background is undefined: /var/www/html/templates/rt_hadron//less/global.less on line 18
An error occurred. Failed to compile.
I did a grep on the filesystem (grep -rnw . -e "@mainbody-background" in my main web folder) for everywhere that @mainbody-background is used and it's used a LOT. But it's never defined anywhere that I can see. Where is this defined in the template, is it something with Gantry? Why would it be undefined?