I had the exact same thing recently. It can be indicative of a battery problem. In my case, I let ran the battery down too much because I was trying debug the audio interface I was installing. I've also read in other threads where someone's battery was failing and he got the same icon.
E89 Z4 sDrive35i 7DCT "Zayna", Alpine White/Coral Red
E92 335i 6MT "Calixta", Space Grey/Coral Red [Retired]