When you just select the head if you want to save an expression, it also saves the "zeroed" channels (Morphdials), so when you apply the expression it turns  every dial that's not used in the expression to zero leaving you with the default face. Injection pose-builder, a program sold by  DAZ3D, can be used to repair your expressions and make INJ and REM thumbnails for it. The original version doesn´t come with V4 support, but I believe there was a thread some days ago how to import that. It can also be used for poses.

Best regards,

Bopperthijs

-How can you improve things when you don't make mistakes?