Now, this was just a quick tutorial on how to manage SPNs. This hole can go pretty deep. Here’s a decent link on MSDN for troubleshooting SPNs. I don’t think I like their troubleshooting because they don’t really do a good job of showing you the commands, but it’s a good explanation of the problem, what an SPN is, etc. If I remember correctly it’ll also help you choose the right SPN.
This is a classic example of a bad Microsoft error. In this case, it’s bad because there are multiple root causes for the same error and because the message itself is unhelpful.