It appears that a recent Windows Update has solved a number of both graphics and download issues. Unfortunately, this update may have gotten "stuck" for some users. In order to fix it, do the following. Please note that you must upgrade to Windows 8.1 if you haven't already in order for this to work.
- Press the Windows key
- Type in Windows Update
- Under the search bar you see on the right, choose Check for Updates
- In the Windows Update screen, press the Check Now button
- Even if it doesn't seem to find any updates, click on View Details
- Install any updates you see that haven't been installed - including optional ones
- Press Ctrl, Alt & Delete at the same time. You will see a white icon in the bottom right corner. Click on that and select Restart from the menu.
If this does not fix your issue, you may need to uninstall and reinstall your game. You may also need to repeat the above steps a second time.