I have had the latest patch 1.9 since its release and this command was working 2 days ago. When I started playing again today it presented the above error. So I did a cache verification to make sure nothing was wrong; 1 file was fixed.
Below is an example of what I've actually typed on a brand new character generated without any mods installed subsequent to verifying my cache:
incpcs destruction 1
The error still occurs.
Did patch 1.9 turn off this console command when it modified "fixed" the Oghma Infinium glitch?
Regards,
Bram

strange, I've been typing incpc
that works just fine! Not sure why the other way stopped working since it was 2 days ago, but
who knows.