It's an odd one, cos I already use an 'if mats:'. I stuck a message box either side of it like this.

poser.DialogSimple.MessageBox("Gonna do 'if mats'")
if mats:
    poser.DialogSimple.MessageBox("Done 'if mats'")

When I run the script the first message box (Gonna do 'if mats') appears, but then I get the Python print window with this

poser.error: Actor has no available material

I'm puzzled - the whole purpose of the 'if mats:' is to check for this. Still trying to make sense of this.

 

---

The 3Dcheapskate* occasionally posts sensible stuff. Usually by accident.
And it usually uses Poser 11, with units set to inches. Except when it's using Poser 6 or PP2014, or when its units are set to PNU.

*also available in ShareCG, DAZ, and HiveWire3D flavours (the DeviantArt and CGBytes flavour have been discontinued).