Navigation System

I have been getting a Disc error - see dealer on my navigation screen when I crank my car and then it goes black. I thought that may be the disc needed to be updated so I purchased a 2016 navigation update disc. I ejected the old disc, I noticed that the disc did not seem to come out all the way because it was hard to get a grip on it to pull it out. When I did get it out, the disk has a reddish brown powder substance on it (front and back). It easily wiped off. I tried to upload the new disc but still received same error after inserting. I ejected my new updated disc and it has the same reddish brown substance on it. Not sure what to do now, please help. I have only had the vehicle 1 year and it worked perfectly up until about 3 months ago.