Space Shooter Hazards Not Spawning

Upon completion of lesson 15: "Counting Points and Displaying the Score" I ran into an issue with my project.

For reference I am running Unity version 4.6.2f1

Hazards no longer spawn upon starting the game, the ship flies and shoots normally, but no steroids either appear on the hierarchy, or are visible on the game screen. I changed none of the settings in the Game Controller Script Interface and all of my C# scripts are identical to the instructors with the minor exception of having to adjust the Score Text script due to the instructional video being made with an older version of Unity and GUItext no longer being a create-able game object.

Upon playing the game I receive this error log in the console and I believe this is causing my issue:

As stated earlier, the line in the code earlier is identical to the instructors, but he does not receive said error message and his game runs normally. Here is my Game Controller script for reference. Since I am not fluent in C# I do not know to set this to an instance of an object. Any help is appreciated!

     void UpdateScore()
 {
     scoreText.text = "Score: " + score;
 }