If so, please do not update to Viber 5.4.1 for the time being. Please let us know if restoring Viber to version 5.4 (or earlier) via iTunes restored your messages to your account. If you’re not sure how to do that, please see this link: Make sure you have backed up your data via iTunes before the 28th June (i.e before Viber 5.4.1 was released).

Disable automatic updates on your device before attempting to restore your iTunes back up (so Viber does not update back to Viber 5.4.1).

If you backed up your phone via iTunes, please try the following: Unfortunately, this procedure may not work if you backed up your phone via iCloud instead of iTunes, or if you did not back up your device at all. 'We have been working hard to find a solution for our users we are now testing a possible solution that may allow you to retrieve some of the messages on your account if you have performed an iTunes back up before Viber updated to version 5.4.1. I persisted and have received the following response, which I'm yet to try:

I also emailed Viber and they initially said nothing could be done. Hi, I also had exactly the same experience yesterday, in identical circumstances to those outlined by David Cowling and freekidolpinz.

Did viber update