Importing FBX went wrong

Hello, im making a game and so far i've been importing my characters without any problem, but today when i imported a character i been working on im having this error, and also the character looks all black (like if normals were flipped, but thats not the case because i triple checked the normals).
even so, in the project window i cant see the model, its just blank. and usually i can see a mini-version of the model in the project window.
i dont know what it is, and how i can fix it.
i accept suggestions to try stuff

btw, im using blender for 3d editing.