Video subtitles aren't showing in exe

I am currently evaulating HTML Executable and have HTML pages that will play .mp4 files. When opened locally, the videos are able to show subtitles from a .vtt file, however when the html page is viewed from within the .exe, the subtitles do not show. Are subtitles supported in the .exe created by HTML Executable?

They are not handled by the internal Webbrowser engine, so subtitles won’t be showed. Unless you have some Flash-based MP4 player which could do it.