How to add color, gradient and other effects on a Fresco document in Illustrator

Hello.

I am using Fresco and illustrator on Windows. When I send a Vector drawing from Fresco to Illustrator I am unable to color it or use the gradient tool on it. It is only two layer: the background and the vector line drawing. When I bring it into Illustrator I select the gradient tool or the paint tool, but  I keep getting the "not allowed symbol" (circle with the slash through it icon) every time I hover over my illustration. I am more new to Illustrator so maybe there's an easy fix, but I can't find an answer or figure it out.