Fatal exception occurred. Program will exit.

I tried for my first time to create a jar file out of a program that I created in JCreator LE. I looked up tutorials online on how to do this, and I created the .jar, and edited the file in Meta-Inf as was on the video. I go to run it and I get this error. When I build and run in JCreator I get only this error:
Note: C:\Users\Matthew\Documents\JCreator LE\MyProjects\Gomoku\classes\Gomoku.java uses or overrides a deprecated API.
Note: Recompile with -Xlint:deprecation for details.
I fixed all other errors, and I just need to know how to fix this (if it indeed is the problem)

The error indicates you are relying on deprecated functionality from either a class or a method no longer supported. It should still work, but any time in the future it may be removed from the Java API and will fail to work from that point forward.
Execute the javac with -deprecation and it should tell you what in particular is causing this. Looks to me that Gomoku may override a deprecated class.
Then go to the API for that class or method, and see what they suggest should be used instead.