Issue description
This is similar to what happened with some of the previous mobs with custom models (the texture is purple and black), however this time it doesn't work even after reinstalling MCreator (while reinstalling MCreator always made the models work previously).
I will also send you the workspace with an email soon.
I got the workspace you sent.
The issue is that your mob texture is called EarthBeast.png. MCreator generally lowercases all file names for you. Minecraft standard is all lowercase file names.
If you rename this file to earhbeast.png and select this one for the mob, the texture will work.
Did you manually place this texture in MCreator or how did you import it?