For clarity to our users, I want to share here the cause of the downtime that we had the 5th of December.
On that day we had to migrate the servers that are currently hosting demo.bpmn.io. The procedure has been tested before on other hosts and we were expecting a short downtime. Unfortunately something happened that we didn’t predict.
More in details, we found ourselves unable to verify the domain using letsencrypt and, for this reason, we didn’t manage to get a new ssl certificate. For this reason the downtime, that should have been minimal, lasted way longer than we expected.
It took us quite some time to debug a nasty issue in our DNS configuration that was preventing the domain from being validated. As soon as the issue has been understood and corrected we managed to generate a new ssl certificate and bring the website back online.
Sorry for the inconvenience, we will try to put in place measures in order to not encounter this problem again.