How to fix "bone heat weighting failed to find solution for one or more bones" I tried everything! I have tried every solution i could find here and nothing seems to be working. I'm a beginner I only know the basics. Can someone help me with it?  

Here is the blend file:

https://drive.google.com/open?id=10Y7lKjOV4p28ZmlqfE-aOFoxmD8g8PuU

If someone can fix it i would be so grateful.

Edit: i tried Remove Doubles, didn't work.
i find the error come from your hairmesh
this may solve the problem