Error Enabling Lucene in Orchard

Topics: Installing Orchard, Troubleshooting
Jul 4 at 6:30 AM
Hello folks, newbie question that my Google skills are failing to solve.
I have Orchard deployed to Azure.
I'm following the instructions here to create a site search:

I've installed Lucene but when I try to enable it I get the error:
No loader found for feature's ("Lucene") exension!

Any ideas what I'm doing wrong?