Hi Tessa,
Thank you for contacting us, and I’m sorry to hear about the issue you’re experiencing after the recent iOS update. The good news is, if you still know your password to mSecure 4, you haven’t lost your data. All you would need to do is install mSecure 5 on the same iOS device mSecure 4 is installed, create a new account or reset an existing account, and then migrate your data in from the old app. You can find out more about this process here: https://support.msecure.com/en/support/discussions/topics/36000020017
Tessa