For 1.14.4 btw
Whenever I make an element or import a texture, it compiles fine, but when it generates a thumbnail it just makes an invisible box. Inside the modElementThumbnails folder where they all are, they are just transparent images. And they work fine in minecraft.
I make my textures (for block, item and everything else) in GIMP and none of them render in the application.
But, here's the strange thing, when I use an already made texture (like from another mod) it works fine. Also in the texture animation bit they render fine and the default minecraft blocks and items work fine even if I import them from the textures file. My workspace ends up looking like this:
My brother who also uses Mcreator, uses GIMP to create his textures too. When he imports them the thumbnails generate fine.
I have tried re-installing, whenever there is a new update the issue persists.