Automatic weights deforming my character I'm having problems when I want to set the mesh as the armature parent. Once I press Ctrl+P to open the menu and select "With automatic weights" it deforms the mesh.
Select your mesh
Delete the armature modifier it has and delete it's parent and delete all vertex groups
Select your armature
Switch to Pose mode
Select all bones
Press Space Bar and write 

Apply Pose as Rest Pose
Select mesh then armature then Ctrl+P and choose with automatic weighting