when i try uploading a character, it says "sorry, unable to map your existing skeleton."

[Kosmonaut42]

Hi, so I am really new to blender and 3D modeling. I need to rig something for a class, and I heard Mixamo is the best way, but when I try uploading, it has said "sorry, unable to map your existing skeleton." every time except for once, when it uploaded but was just blank with nothing there. I need to finish my project very soon, and would apreciate help. attatched I have a screenshot of the thing that pops up.

[Kosmonaut42]

also here is the figure i'm trying to rig:

https://drive.google.com/file/d/1oZgHNPPyXrSYTeZrqKEB477AGcTwulKo/view?usp=sharing

[Ussnorway]

wow

1. 87 mb is too big... i'd cut that in half
2. your model has no hands and will never rig to a standard human ... your only real chance is claws
3. as you are using Blender, I'd full the model in so it is solid

[Lefébure 23993603lbpu]

Hi! 

I just got the same error. Here is how I fix it:

First, make sure your model is not to heavy. Decimate it if necessary. (I did it in Zbrush with Decimate Master but I heard it was possible in Blender too.)

Once your model is optimized, delete the MAT attributed, and assign a brand new one. 

Export in fbx, and try to upload it in Mixamo. 

Keep me posted if that helps.