Heads up, this posting’s title was “User credentials could not be delegated and Active Directory” but I realized I needed a title that evoked my emotional state  😉 Do not fret or worry, this is not “yet another user credentials delegation” blog. After all, there are already the postings including Troubleshooting #PowerPivot Excel Services connectivity (written by yours truly) and Excel Services delegation (by PowerPivotTwins partner Dave Wickert).   More importantly, if you want to debug and troubleshoot your way through the PowerPivot / Excel Services delegation issues, the coup-de-grace is Lee Graber’s excellent post: that The data connection uses…