If you are having an issue and haven't tried reinstalling recently, try uninstalling the program, removing the NPRoblox.plugin file, and reinstalling using the steps located at the bottom of the following two articles:
Other Things to Try
If uninstalling and reinstalling did not help, please try the following
- Make sure you are using one of the supported Mac OS versions: 10.6 and higher.
- Currently only the Intel chipset is supported. The Motorola Power PC is not supported.
- If you are currently using the Safari web browser and having an issue, try using one of our supported browsers such as Internet Explorer, Firefox or Google Chrome.
- Check to make sure that the Roblox icon is currently on your Dock and the Roblox Application is showing in your Applications folder.
- Try launching the program from the Dock if you're having a problem playing a game from the website.
- Try fully resetting your Roblox settings by deleting the settings files. To do this go to Library->Preferences and delete all of the Roblox com files. When Studio/Player are launched again, it should reinstall them all.