I've had this problem come and then go. It happens under seemingly identical printing conditions and the same X3g files.

Flashforge Creator (wood model)
Hatchbox ABS 1.75mm
230 degC extruder
110 degC glass bed with Kapton
speeds of 50/80 to 65/90 tried

1117142010.jpg

I don't think it's a filament problem, because it's occurred on two separate prints in the same locations. I am however wondering if it is a temperature or speed problem. My other guess is that it is related to the part warping during the print and basically squishing the still soft plastic out the sides.