What does "Not Enough Raw Materials" mean, and how do I fix it? I can't get oil either.
As far as I know, you don't have any direct control of what you import into your city. However, you can create more points of import by building Cargo Terminals for trains and Cargo Harbours for boats. Just make sure the train stations are connected to tracks going to the outside world. You can also increase your cities own production by building industrial sectors. Use the oil specialization to get more oil if there's any on your map.