I had this error code pop up the last time I charged my pack. To clear the error code I just hit the sleep switch, and then turned it back on and the error didn't return.
However, I charged it again today and got the error code again. I sent these pic's to Ian and will await his reply. I did get an auto-response from Ian that he's on vacation and will get back to all inquiries when he returns. I'll post "what's up" when I know.