Evercross EK6 E-9 code

[revicm]

Hi all. New to the site. I bought 2 Evercross K6 folding bikes. Mine has worked fine so far but my wife's threw a E9 code. Brake error light was on but is now off. I can't clear the code and swapped the controller with no change. Is there a hard reset on these bikes? I did remove the battery etc.