On 19th July 2019 at 15:30 UTC certificate used to serve traffic from ucarecdn.com and www.ucarecdn.com has expired. All HTTPS traffic to these domains effectively stopped.
We were able to quickly (within minutes) redirect www.ucarecdn.com traffic to alternative CDN provider with proper certificate installed.
It took us approximately 105 minutes since start of the incident to fix the issue with ucarecdn.com.