Me too. I got it today for the second time, in the 600s BC. Last time I got it was when I played on after winning for a couple of turns so it didn't bother me too much. Reloaded and tried again, moving a unit a different way, but it happened again, same turn same unit (a barb warrior) moving (tho in a different direction).
This has happened to me too, more times than I care to remember actually. However, there may be a light at the end of the error message tunnel for you as there was for me.
Try disabling "Show Civil Disorder Pop up" in preferences. That worked for me. In addition, if you're currently playing a game on a map that was customized in the editor, make sure that you haven't renamed any units. Even though Firaxis opted to include a "rename" feature for the game's units in the editor, actually renaming one is a sure-fire way to get an error message like the one you described.
These problems have been discussed in the above thread, "What's up with Civ. exe... Just thought you might not have seen them... Don't hold your breath on the fixes, and tell all your gamer friends not to sink thier money in this game until something is done about it.