Before posting about a problem you're encountering, please review the possible solutions below. An installation guide for the gamemode can be found here[www.pixeltailgames.com]. For a list of convars and more info, check out the wiki[github.com]

Garry's Mod is using a browser technology called Awesomium which is based on Chrome 18, a very outdated version. Many of the required HTML5 features for video playback aren't supported in Awesomium, and thus not supported in GMod/Cinema. For progress on fixing this issue, please see the feature request on GitHub[github.com].

Follow the installation guide here[cinema.pixeltailgames.com] to install the NPAPI version of Adobe Flash Player.

Open up console by pressing ~ and type in mat_dxlevel 90

Try subscribing to the cinema_theatron map on workshop. The basement theater requires Half-Life 2: Episode 2 to be mounted in GMod.

Hold tab, left-click anywhere on the screen and then drag the volume bar on the right side of the scoreboard. Alternatively, you can increment/decrement the volume by 10% using +/- respectively. Note that the volume can't be changed on Twitch streams as there's currently no way to do so programmatically.

Method 1: While in a theater, hold Q to show the theater actions menu. On the left menu, select "Request Video." A menu will open in which you can navigate video providers to find a video of your choice. Once you've found the video you want, you can press the "Request URL" button to the right of the URL address bar. The button will be colored red if the video you're viewing is valid for the Cinema gamemode.
Method 2: Find a video URL (must be supported by Cinema) and paste it into the chat. Upon pressing enter, it should say the video has been requested.

If you're using a touchpad, there may be software delaying clicks after typing; this needs to be disabled. In Windows 8, the delay can be turned off in the mouse and touchpad settings.

You haven't selected the Cinema gamemode on the main menu. Follow these installation instructions[www.pixeltailgames.com] to find how to start a game using the Cinema gamemode. If you're trying to run a dedicated server, it also needs to be subscribed to the content. Read the question below for more info.

After setting up a dedicated server[wiki.garrysmod.com], you can have your server subscribe to Steam Workshop addons by following this tutorial[wiki.garrysmod.com]. The collection you'll want to use is here. Remember to configure your server to use the cinema gamemode by adding "gamemode cinema" to server.cfg.

If you're a Mac user, I'm afraid this is an issue yet to be resolved. The problem is likely to be an issue with Garry's Mod itself. In any case, you can try updating your version of Adobe Flash (for "Other Browsers").

If you're a Windows user, try accessing the Volume Mixer (Image[samuelmaddock.com]) through the task bar and make sure that Awesomium's volume slider is set properly. You must be in-game and in a theater for the Awesomium process to appear.

If you're playing on a public server, it's possible that the errors are due to custom server modifications or that they need to update the gamemode. If you're positive that this is not the case, feel free to post the error (copy from the console) and I'll look into it.

Set cinema_allow_voice to 1 in your server.cfg file. Other convars can be found on the wiki.[github.com]

Yes. The convar cinema_queue_mode can be used to change the video queue between two modes.
1 = Videos may be voted up or down
2 = Videos are played in the order they're requested.

The Cinema gamemode doesn't inherit the Sandbox gamemode functionality. The following are a few solutions for watching videos with Sandbox features:

• Use the Media Player addon
  
• Use PlayX
  
• Edit the Cinema gamemode's Lua code[github.com] to derive from the Sandbox gamemode.

Any non-timed video is restricted to private theaters.

Please ask the developers of GMod to update Awesomium[github.com], this issue is out of my control. :(

Currently Cinema doesn't support a visual way to change your player model. However, it's possible to change your player model using the convar cl_playermodel in any gamemode.

The server you're playing on is running an older version of the Cinema gamemode. They'll need to update to the latest version for fixed YouTube support.