BeagleboneBlack Wireless Ubuntu 16.04 PWM produces "RuntimeError: Problem with the cape manager"

I have a beagleboneblack wireless with Ubuntu xenial 16.04. I am trying to use the Adafruit_BBIO library and I am following these instructions : .

Following the tutorials provided in adafruit’s webpage, I set up some GPIO ports successfully. However, when I try to set up a PWM port, the following runtime error occurs:

I have found similar threads here:,, I have tried most of the solutions suggested in these forums, without any luck so far.