The asset ZIP you attached to v1.0.4 is invalid;

You have TWO nested folders;
Current: PetWalker-1.0.4.zip\PetWalker-1.0.4\PetWalker\PetWalker.toc
Expected: PetWalker-1.0.4.zip\PetWalker\PetWalker.toc

I hope this helps :)

Thanks for the hint! Just uploaded a new archive with just "PetWalker" as root folder. (Like the one on Wago.)

(The nested folders were an attempt to make it compliant with WoWUp Hub.)