Happened to me again on Sat, off road in Wales. Was below zero degrees, and had been hammering it. Bike started feeling a bit weird (wooden), but put it down to the ground being slippery. Then I noticed the ESA error. Would not clear by switching bike off with key. Cleared it in the end by changing riding modes, and was fine for rest of the day. Hopefully fault logged in the computer and can be diagnosed / fixed.
Both times it has happened with me has been after hammering it off road. Once when north of 30 degrees, other when below zero; so hardly an overheating issue.