WARNING: You should only reset your BlueStacks user data if told to do so by a BlueStacks representative. Doing so will remove all of your installed apps and the associated app data. There is no way to recover your apps or data after performing a reset. Here are the steps required to reset your user data:
1) From Finder, hold down the OPTION key, click on the `Go' menu and select `Library'.
2) From the Library folder, select `BlueStacks App Player' and then `Uninstall'.
3) From the Uninstall folder, run the `Clear BlueStacks User Data' tool.
4) The tool will ask if you wish to preserve or delete your applications. Click `Delete' to continue.
5) Wait for the tool to complete. When you see the following popup, click `OK'.
6) Start BlueStacks from the Applications folder. This will kick off the same setup workflow that it used for your initial BlueStacks installation.