Error message when trying to open Messages.

Question

Just upgraded to Mountain Lion (10.8) yesterday. Messages won't open. Reports "An Internal Messages error occurred. There was a problem with Messages. You need to quit and open Messages again."
Console shows: 7/29/12 8:53:41.594 PM Messages[834]: [Warning] Bad response from daemon for setup info
Anyone have any thoughts on what might be causing this?
I did have iChat in a subdirectory within applications, but the install blew it away. Some arcane .plist somewhere?
Oh, also I had system prefs in "Utilities" directory and it did not get blown away by the new install. Instead, it remained behind and I had to remove it as root user, leaving the correct system prefs in "Applications."
MacBook Pro 2008; 6 gb ram; hybrid SSD/SATA drive; OS X 10.8. Can't think of anything else to include that might be relevant. Ask if I forgot something, and I'll post it.
Any assistance that you may provide in resolving this little glitch would be sincerely appreciated. 
James Reid
Sierra Foothills
Northern California

Answer 1

@Ralph       Thanks. Here's how I proceeded with your suggestions.
Try moving these as well.
Indeed, there were some files as you described in the "By Host" directory. I removed those, trashing them, and, for good measure re-examined the parent directory (Library), removing any (newly created for the most part) files matching the .plist list provided in your post.
IF you are really sure the com.apple.ichat.plist one is not there you need to check if you have Permissions to Write to the Preferences folder.
Hmm. Perhaps I could've been clearer in my post: the com.apple.ichat.plist was the only one of those files you specified that actually was in the prefs directory. Nonetheless I carried out your instructions to check for ownership and determined that, indeed, the ownership of the Preferences directory was corrrectly ascribed to the user from which I checked this-- my main user account (same that is having difficulty with starting Messages, to be perfectly clear).
The plot, though 'twas not thick enough, yet thickens more:
By chance I opened FaceTime, which I don't often use on my laptop, and attempted to sign in. The app opened successfully, but when I filled in my user name and submitted, it failed to connect to Apple. I went to Preferences and tossed out all the FaceTime .plists. (including one in the By Host directory).
This didn't help. I tried filling in my AppleID user data to "open a new account." FaceTime immediately connected and told me that a user with that email already exists, would I like to use this information to log in. "Yes," I eagerly replied.
FaceTime switched back to the login screen with the AppleID and password pre-filled, but when I submitted the form, it again failed to log in, after some considerable time, it returned the error you see to the left.
Also relevant are the facts that I checked the Firewall setting (on) and created rules in Little Snitch to allow both FaceTime and Messages both incoming and outgoing connections.
And so, despite our commendable collective efforts, we've not yet prevailed. Since the purchase of Mountain Lion was recent, perhaps it is getting to be time to give Apple a call and see if, based on that purchase, they are willing to speak with me and try and troubleshoot the situation.
Thanks again for your perseverance and help. I remain open to suggestions, should any further thoughts occur to you.
Best regards,
codefish46