FYI, the environment that allows you to run OS 9 apps in OS X is called Classic. If you have never successfully run Classic before, it's probably because your OS 9 system folder has an extension that is incompatible with Classic. Go into System Preferences, select Classic, then click on the advanced tab and select to start with extensions off. Once you do this, Classic should complete its startup.
If it does start properly, you know it's an issue with a third party extension. You can later go into the same advanced tab of the Classic pane and choose to start up with the extensions manager. Once you do, you'll be presented with the extensions manager window where you can choose the Mac OS 9.x Base set. That will disable the third party extension presumably causing the issue, and you should be able to start Classic normally afterward.