Due to trouble with ABS print adhering when printing long narrow item, curling edges, I changed for the first time to PLA (Microcenter/Inland) this past week. It then printed the same ribbed edges as you got. In Simplify3D, I changed the filament diameter to something smaller, 1.7, and the rib edges are completely gone. PLA now printing as well as ABS, can run my nail down the side and it's absolutely smooth. One odd thing still happening with PLA, it was consistently not extruding the first inch of the print.

I then changed to another color PLA and noticed the filament holder is custom to FlashForge specific spools and when snapping on Microcenter's, it's not really seated on the spool and therefore unable to roll off smoothly. I ran a small test and this one has drag so much that the extruder's having a hard time pulling the filament in, BIG gaps in the first layer. I was just going to snap the flanges off the ends of the FlashForge spool holders to get rid of the drag but then I'd have to finagle something to keep the spools from dropping off, as they unwound. I'm stopping to print new ones from thingiverse.

So, two thoughts, possibly you need to drop the diameter setting for your filament and/or your spool holder is dragging preventing the appropriate amount of filament from extruding.