Shortcat would not import its license file (named "shortcat-license") through the "Add License" button (where the file appeared as greyed out), via drag and drop into the License window, or via drag and drop onto Shortcat.app.
Resolved by finding which file extension Shortcat was associated with in /Applications/Shortcat.app/Contents/Info.plist → CFBundleTypeExtensions*:
<key>CFBundleTypeExtensions</key>
<array>
<string>shortcat-license</string>
</array>Just needed to add any filename and a dot before "shortcat-license", which turned out to be an extension rather than a filename.
* From the CFBundleDocumentTypes documentation:
Key: CFBundleTypeExtensions
Xcode name: "Document Extensions"
Description: This key contains an array of strings. Each string contains a filename extension (minus the leading period) to map to this document type. To open documents with any extension, specify an extension with a single asterisk "*". (In OS X v10.4, this key is ignored if the LSItemContentTypes key is present.) Deprecated in OS X v10.5.
/mac | Mar 25, 2022