When i installed the unoffical 3.17 patch(Version 1.09) with the 50 civ dll the graphics became altered in a weird way as shown below. (Note:This problem dissapeared when i redownloaded the patch without the 50 civ dll.)

I used the 50 civ dll without any problems. You might have had a corrupted download, or something else is going on on your machine. Try to re-download the 50 Civs dll, compare its size to that of the regular unofficial patch dll 8they should be identical), and try to use it again.