A reminder to readers/those who've not stayed on top of their alerts: Amazon CloudFront (the cloud-based Content Delivery Network) is deprecating Real-Time Messaging Protocol (RTMP) distributions on December 31: if you use CloudFront + Adobe Flash Media Server to stream media, things will break at that point, then vanish.
RTMP is used by Adobe Flash Media Server (which has been used for years by many customers alongside EC2 and the CloudFront CDN to stream live audio or video). The move comes on the back of Adobe's long-signalled (since July 2017) end-of-life for Flash; also occuring on December 31 -- and set to break many older, animation-rich websites.
"On that day CloudFront RTMP distributions will be deleted" warned Amazon 12 months ago in a community post.
"[January 1 2021 onwards] CloudFront will deny requests made to those previously existing endpoints. All RTMP workloads should begin migrating to a standard CloudFront Web distribution and use one of several HTTP streaming protocols such as HTTP Live Streaming, Dynamic Adaptive Streaming over HTTP, Microsoft Smooth Streaming, or HTTP Dynamic Streaming," Amazon warned Dec. 17, 2019.
n.b. Customers using CloudFront to serve a media player and media files may have set up a web distribution for the media player, and an RTMP distribution for the media files. There are plentiful migration options and users would have had to ignored many warnings to neglect the shift, but as the internet is held together with gaffer tape, there's usually an important corner somewhere that will take a hit.
(Dig about a bit, and you'll find a way to re-create your distribution to have similar cache configuration settings).
Experts meanwhile say older un-maintained websites -- including many educational ones reliant on Flash animations -- are likely to bear the brunt of Flash's own deprecation December 31.
As Adobe earlier noted, "Since open standards such as HTML5, WebGL and WebAssembly are continually maturing to serve as viable alternatives for Flash content, most browser vendors are integrating these open standards into their browsers and deprecating third-party plug-ins.
"However, some enterprise customers may still require Flash Player commercial support and licensing beyond 2020 to run internal business systems (i.e. content on a company’s intranet, interactive dashboards, digital training)." Those enterprise customers in this boat should contact [Adobe' official distribution licensing partner] HARMAN "to see what options are available" Adobe notes.