Also, add 'layers.loader.LayerLoader' to your TEMPLATE_LOADERS
It should read something like:
Add 'layers.loader.LayerLoader' at the top of your TEMPLATE_LOADERS, prior to
any 'django.template.loaders':
TEMPLATE_LOADERS = (
'layers.loader.LayerLoader',
'django.template.loaders.filesystem.Loader',
'django.template.loaders.app_directories.Loader',
)
The documentation reads:
It should read something like: