Firstly, if you are having problems with the flash player try using different browser to view the apps on Facebook. If the same problem occurs try using a different browser: you may need to uninstall your flash player and reinstall it. The link provided is the official site for Adobe products, you will be able to download and install the latest flash player available if you require an updated version and other Adobe products at this site http://www.adobe.com/downloads/
Secondly, if after using a different browser and the flash player responds fine viewing Facebook apps, then it is not the flash player, but the previous browser you used that is not responding, in this case you can uninstall the specific browser and reinstall it. I do hope this resolved the problem you are experiencing.