Sometimes you may have difficulty logging in or connecting to games using your iDevice. If this happens, one possible solution may be to clear out your device's cookies and log in again. Luckily, this should be relatively simple to do. For steps on how to clear out this information, please click here.
Once the cookies have been cleared, restart your device. After this your Roblox cookies should be successfully removed.
For more information on other mobile related matters, please see the following links: