A note: I have a wonky internet connection so this glitch may be due to a corrupt download on my part. This tutorial has three ways to deal with the glitch without attempting the redownload the toolkit.
Solution 1: Press ctrl to skip this message.
If you haven't yet included any battle system, which is likely if you are following the quick guide, you can skip this and go straight to the game with the ctrl key.
Sometimes RPGtoolkit crashed while I was doing this.
Solution 2: Remove the plugin
If you don't plan to have fighting in the game, you can disable fighting under the fighting tab. Even if you do, it may be best to disable until you have made your own fighting system.
After disabling fighting in game, save.
Now go to the plugins tab, and remove the "fight system plugin". Then save again and the game should be good to go.
Solution 3: Your own battle system:
If you want to include battle, however, you will likely either have to find a non corrupt version of the battle system dll, or use RPG code to write your own battle system. If so, go to the fight screen, select "yes" and go to the edit menu. Look for the option to use the built in fighting system, and select "No, Run Program". From there you can add in your own program.
You will still need to remove the plugin from the fighting system, see solution 2.