Hey Graham
This is where it gets super tricky, and why it's usually a good idea to steer clear of customising this space. Sounds like the format of that property isn't correct, and we don't have it well documented so understandable.
The other thing (mentioned in the comments) is that, as soon as you use that property, it blows away existing categories.
// [OPTIONAL] Create wizard customisations
// If this configuration is present it will determine the categories and asset types
// and their order in the create wizard.
createWizardCategories: {
'My Custom Stuff': {
assets: [
{
type_code: 'folder',
display_name: 'My Custom Folder',
interface_type: 'wizard_default',
description: 'My custom folder description.'
},
{
type_code: 'data_record',
display_name: 'Custom Data Record',
interface_type: 'wizard_default',
description: 'My custom data record description.'
},
{
type_code: 'data_record',
display_name: 'Custom Data Record',
interface_type: 'wizard_default',
description: 'My custom data record description.'
}
]
} // End
}, // Specifying anything here will completely replace any defaults
The best way to understand what can be used in that property is to look at how the existing categories are already coded by downloading package to desktop (http://manuals.matrix.squizsuite.net/download-ees) and opening ees > Libs > wizards > EasyEditAssetWizardManager.js and "var AssetWizardCategoryData" at the top.