If you cannot remember the security question, there is no official "master paper" or back-door code to bypass the encryption. The only way to remove the lock is a , which will delete all data on the phone, including your hidden files. Power off the device. Hold Power + Volume Up to enter Recovery Mode.

This may restore the app to default settings and could result in losing access to hidden files. before attempting a reset?

Sometimes, XHide allows you to open the app via the phone's dialer, even if the icon is hidden. Open your phone's dialer app.