There has been no change in the media code in the release branch for many, many months. So, if something that used to work stopped working a few days ago, it's either an issue with your system (did you update the OS or one of its media-related components ?), or with the media source; of course, without a log, I can't tell for sure what issue you are encountering and where it comes from...
You shall expect many sources to switch from Quicktime and Flash to HTML5 (this is already the case for Youtube & Co) since the latter two standards are utterly deprecated, the problem being that the current release viewers (all of them) cannot deal with HTML5 (because they rely on an old, non-HTML5-aware version of QtWebkit).
This is why LL started to develop the CEF3 plugin, which the experimental branch of the Cool VL Viewer already implements as well. See
this thread for details. Note also that the CEF3 plugin will
NOT support Flash neither Quicktime and that all scripted TV makers will have to switch to pure HTML5 sources if they want their product to keep working with future viewers (but this will also break their product on current viewers, so do expect quite some ruckus in the coming weeks/months: for this reason, the Cool VL Viewer will keep both the old QtWebkit-based plugin and the new CEF3-based one for a while).