Unable to access config'd custom xmp namespace in exiftool

Question

Though some form of me just not really getting it, I am unable to write this custom XMP namespace I've made in my config file. Below is the file.

%Image::Exiftool::UserDefined = (
  'Image::ExifTool::XMP::Main' => {
    galex => { SubDirectory => { TagTable => 'Image::ExifTool::UserDefined::galex' }}
  }
);

%Image::ExifTool::UserDefined::galex = (
    GROUPS => { 0 => 'XMP', 1 => 'XMP-galex', 2 => 'Image' },
    NAMESPACE => { 'galex' => 'http://atlasjan.sdf.org/xml/galex.xsd' },
    WRITABLE => 'string', # default to string-type tags
    Include => { Writable => 'boolean' },
    Explicit => { Writable => 'boolean' },
    Spoiler => { Writable => 'boolean' },
    Comment => { Writable => 'string' },
);

So far I've tried...

exiftool -xmp:Explicit=true example.png

exiftool -xmp-galex:Explicit=true example.png

and both return a "not defined" error. Where am I going wrong?

Answer 1

The first line should be
%Image::ExifTool::UserDefined = (
not
%Image::Exiftool::UserDefined = (

The T needs to be capitalized in ExifTool. I copy/pasted your config file, fixed the T, and it appeared to work correctly for me.