I figured out what's wrong, and now it works for me:
Under all the files extracted from the theme tarball, there's a file called metacity-theme-1.xml
. You can see it at the bottom of the screenshot I attached; it's the highlighted file. Open that in a text editor. The top of the file should look like this:
<?xml version="1.0"?>
<metacity_theme>
<info>
<name>Humanoid-OSX-Black-ColourButtons</name>
<author>wonkoWonka</author>
<copyright>none</copyright>
<date>June 2018</date>
<description>Black Mac OSX, w/ Coloured buttons by Humanoid, modded by Jiiprah, and again by wonkoWonka.
</description>
<!-- Special thanks to the script kiddie who defaced the author and description. Your special. >
</info>
Right before the </info>
, and right after the fragment special.
, should be -->
(to terminate the comment about "defacing", whatever that comment even means). Instead, a single >
appears. Add two hyphens (--
) before the >
. The file should now look like this:
<?xml version="1.0"?>
<metacity_theme>
<info>
<name>Humanoid-OSX-Black-ColourButtons</name>
<author>wonkoWonka</author>
<copyright>none</copyright>
<date>June 2018</date>
<description>Black Mac OSX, w/ Coloured buttons by Humanoid, modded by Jiiprah, and again by wonkoWonka.
</description>
<!-- Special thanks to the script kiddie who defaced the author and description. Your special. -->
</info>
Save the file, close your text editor, and switch your window border theme to something else and then back again to this Humanoid theme. The decorations should then appear.
I was thinking about tipping off the maintainer about the problem. But that theme contains so much legacy cruft, and it's been unmaintained for so long, I'm thinking about asking the maintainer if I can take over development.