Can't extrude sketch

[mat_hijs]

I'm trying to extrude a sketch (containing a sketch block), but when I do this, I can't select the profile. I can select the inner or the outer lines and extrude them as surfaces, but that's not what I want. I tried running the sketch doctor, and the only problem I found was a redundand point (the insertion point of the sketch block). I can't imagine this would be the problem, but I even tried to delete that point but I still couldn't extrude the profile.

What could be the problem and how could I fix this?

File is in the attachment.

[mcgyvr · Accepted solution]

The block has issues... Explode the sketch...Edit the sketch.. Right click on any line.. Select "Close Loop" and follow along.. Note the areas it addresses.. 

[JDMather]

Did this come from a dwg file?

If yes, can you Attach the original file here?

[mat_hijs]

It did indeed come from a dwg, I edited the dwg in autocad to make it a closed loop, make everything right before copying it to inventor. I didn't see any errors about an open loop in the sketch doctor. Now I tried to do as suggested in this thread, and this worked. What's weird though, the point where the loop wasn't closed was created in autocad using the fillet command, so I don't really understand how there can be an opening. Any idea how this can happen though?