Animation-exporting issues, YABEE

Hello to all. I am progressing rather well in terms of developing a blender->.egg pipeline, with great gratitude to the aid I have received thus far from here. I have managed to export multiple animations with no problems, save one. All the animations are armature-based and do show well in blender, but on exporting them to the .egg format, the animations animate with distortions. The attached photo should show what I mean; the actor is in the process of squatting, but there appears to be a stretch on his face, as if part of it is not influenced by the animation. The animation does play well in blender, so I doubt that the issue is related to weight-painting, but given the fact that I’m learning, I could be wrong.

I have attached the relevant blender file. If you are to view it with the intention of helping, please navigate to the “squat” animation in the Action editor; and also link the accompanying image file as the texture. Please note that the rigging, weight-painting and the animation itself are not optimal, but are merely to serve as learning material for developing a proper blender->.egg pipeline on my part. Any help will be appreciated.

[At least the file uploader is working fine! :smiley: ] (1.31 MB)

Some vertices is not attached to the bones. Model is too complex to say what exactly is happened, but you can easy to fix this bug - in weight paint mode select ‘neck’ group and draw across the face with brush.

Thank you very much ninth, that 100% solved the problem. So I now know to double check; even if it may look fine in blender once exported, if there is distortion similar to the one experienced here, I should go back and weight-paint the relevant areas. Thank you again very much.