Automatic weight not working on valve rig I am trying to use rig my mesh with a rig made for valve games however the automatic weights is not working for my mesh.
 i have been following the tutorial shown below that tells me that i am suppose to separate parts blender would have a hard time finding a solution for.
 however this does not seem to be working for me is there anyway to fix this and keep it from happening again

Video:https://www.youtube.com/watch?v=yMARsirE99I&amp;t=7s
Select your mesh then enter into edit mode and select all vertices then choose remove doubles as shown below, this will solve the issue.