Ok, credit where it’s due: I stole even the title of this post from Martin Hatch, and thank all that is holy for him! And thank you Interwebs for keeping everything so nicely archived, and Bing for indexing it, and….
Well, you get the picture. I’m pretty happy about finding an answer to this one, as it was just one more blocker to getting a rush job done for a client. (Isn’t that always the case?)
Anyways, here’s the link to his original post, from July 6, 2009: http://www.martinhatch.com/2009/07/call-to-searchserviceinstanceprovision.html. I’m reposting here just in case I forget where to find the original post.
I don’t know that I ever would have figured this one out, because the error itself it completely useless. But the fix was this:
For the account credentials, when turning on the Search service, use the fully qualified domain credentials. I.e., rather than myuser, use mydomain\myuser. Apparently, this is one place where SharePoint can’t figure out that—even though the rest of the farm is running on domain accounts—this credential set should be a domain account, too.