WFS version 1.4.20 and Lottie files (.json)

I used to be able to add Lottie animations (.json) via the Multimedia component but in the new 1.4.20 version of Watch Face Studio it does not let me upload .json files any more.

Has this been disabled or am I missing something? Any pointers greatly appreciated.

Found the answer in another post - such a pity Lottie .json support seems to have been removed…