Youtube has updated their player, causing it to no longer be compatible with Gmod media players, due to Gmod's old HTML Framework. This issue applies to loading screens and media player addons. If you need it to work, you can opt-in to the "chromium dev branch" of gmod in steam settings. The chromium branch might not support everything you have on your server, so test before recommending it to your players. Once chromium is launched as the main branch, hopefully it will work a lot better. (ETA unknown)
RE: GMOD - YouTube Update - Garry's Mod Game Issues
Obitus Wrote: Youtube has updated their player, causing it to no longer be compatible with Gmod media players, due to Gmod's old HTML Framework. This issue applies to loading screens and media player addons. If you need it to work, you can opt-in to the "chromium dev branch" of gmod in steam settings. The chromium branch might not support everything you have on your server, so test before recommending it to your players. Once chromium is launched as the main branch, hopefully it will work a lot better. (ETA unknown)
I can't see a reason to not just put the chromium on this month update. Awesomium is heavy and slower than pure chromium (due to his age)
Also, pushing a BETA branch on yours players isn't easy at all, the average gmod player are smart as my sofa.