Outlook sync not working using Opacus

We upgraded to latest version of suite and ever since then our Opacus installation is not working. The error message we get is No Sugar CRM REST service was found. Opacus is not responding to us. Please anyone just tell us how do we fix it OR can we use the existing outlook plugin to sync all emails and calendar. Please help!!!

I’ve recently raised an issue with Opacus and had no response, nothing, nada. I’ve tried several approach routes but to no avail. Given we pay for both the activities sync server module and the pro version of the archive plugin, I’m a bit worried.