Playback issues with Internet Explorer and Compatibility Mode
Note: with Flash having been officially retired and Microsoft officially ending support for Internet Explorer parts of this article may no longer be applicable.
The TwentyThree video players supports all modern browsers with HTML5 video playback. This includes Internet Explorer 11 and Edge that fully support HTML5 video.
Internet Explorer versions 7 through 10 are also supported by TwentyThree, but as the browsers do not support HTML5 video, they cannot play videos without using the Flash plugin. This poses some limitations on the video player and experience. For example, older browsers, such as Internet Explorer 8, do not support fullscreen mode, which means that some player controls and subtitles won't be available when turning on fullscreen video playback.
More importantly, if you are browsing videos in Internet Explorer versions 7 through 10 you must have Flash enabled in the browser to play videos in any way.
Compatibility mode in IE11
Sometimes when browsing a web page in an IE11 browser, the page will activate Compatibility Mode, which forces the browser to act like an older version of Internet Explorer. This is often the case on intranets and internal sites using SharePoint. Here, Compatibility Mode is enabled in order to support specific SharePoint features. This effectively turns modern versions of Internet Explorer into a legacy version, meaning that all content, including video, will be handled as if the browser was Internet Explorer 8, even when using newer versions such as Internet Explorer 11.
Therefore, the browser will need to support Flash in order to play any video content on the page.
As Flash is no longer supported nor maintained, many organizations will move to disable Flash support entirely in all browsers. Consequently, this can actually remove video support on many intranet pages if the issue of Compatibility Mode is not addressed.
Recommendations
Our clear recommendation for video support is to use modern browsers including Microsoft Edge or Internet Explorer 11. Both of these browsers have built-in support for the HTML5 video standard, which ensures high-quality playback.
If Compatibility Mode is required for specific applications to work, you will need to make sure Flash is allowed to run in the browser. Otherwise, videos cannot be played.