From one day to the next my Crawl Log went to all *%&%&$.

On every item that was being crawled, a message of The parameter is incorrect was being returned.

I was shocked that this fixed it, but it did!

Central Administration > Operations > Services on Server > Office SharePoint Server

Search Service Settings

I updated the Contact E-mail Address with a new email address, entered the Farm Search Service Account password, and clicked OK.

Fired off a Crawl, and everything was back to normal.