Thank you for contacting us. mSecure 4 is no longer supported, so there will be no updates to that version of the app. mSecure 5 is the update to mSecure 4 that keeps what's happening in iOS 14.5 and 14.6 from happening. It was never our intention to continue the support of mSecure 4, but at the same time, we didn't want to force our customers to upgrade. The problem is, at some point in time, older, unsupported apps always run into issues like this, which is why developers have to provide an option so that it doesn't happen. mSecure 5 is that option.
In the older version of the app, we implemented an advertisement for mSecure 5, and that was to let our users know that the app was available and that they could upgrade at any time. The problem is, we have no way of contacting our older customers, because the older app doesn't have an account system. Without an account system, we don't have their email addresses. If we did have their emails, we would be in communication about what is currently happening. However, issues like iOS 14.5 are a different story altogether. On all our company test devices, we have still not encountered the issue you and other customers are experiencing, which, though there are a lot of people who have experienced the problem, is actually a very small percentage of our overall customer base. Even had we been able to contact you via email, we wouldn't have done so before the iOS 14.5 update, because we never knew it would cause this problem. Also, Apple doesn't send developers notifications that this type of behavior will occur, so there was no way for us to know ahead of time.
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 and 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