Also, I'm looking through your scenes here and you didn't create a new scene collection as Osiris requested, you created just a new scene.
However, I can see some issues with just how your scenes are laid out:
Code:
16:13:41.999: Loaded scenes:
16:13:41.999: - scene 'ma gueule':
16:13:41.999: - source: 'fond' (image_source)
16:13:41.999: - source: 'webcam' (dshow_input)
16:13:41.999: - source: 'chat irc' (window_capture)
16:13:41.999: - filter: 'Rogner' (crop_filter)
16:13:41.999: - filter: 'incrust' (color_key_filter)
16:13:41.999: - scene 'Attente':
16:13:41.999: - source: 'Annonce du jeu' (text_ft2_source)
16:13:41.999: - source: 'fond' (image_source)
16:13:42.000: - source: 'chat irc' (window_capture)
16:13:42.000: - filter: 'Rogner' (crop_filter)
16:13:42.000: - filter: 'incrust' (color_key_filter)
16:13:42.000: - source: 'resau sociaux' (text_ft2_source)
16:13:42.000: - source: 'Bannière_Prep' (text_gdiplus)
16:13:42.000: - source: 'Bannière_Pause' (text_gdiplus)
16:13:42.000: - scene 'Jeux 4:3':
16:13:42.000: - source: 'stéréo mix' (wasapi_input_capture)
16:13:42.000: - source: 'fond' (image_source)
16:13:42.000: - source: 'webcam' (dshow_input)
16:13:42.000: - source: 'hexchat' (window_capture)
16:13:42.000: - filter: 'Rogner' (crop_filter)
16:13:42.000: - filter: 'incruste' (color_key_filter)
16:13:42.000: - source: 'zdaemon' (game_capture)
16:13:42.000: - source: 'Zandro' (game_capture)
16:13:42.000: - source: 'prboom' (game_capture)
16:13:42.000: - source: 'jeu et moteur' (text_ft2_source)
16:13:42.000: - source: 'vlc' (window_capture)
16:13:42.000: - filter: 'Rogner' (crop_filter)
16:13:42.000: - filter: 'Rogner / Encadrer' (crop_filter)
16:13:42.000: - source: 'SNES' (game_capture)
16:13:42.000: - source: 'UT2004' (game_capture)
16:13:42.000: - source: 'Momodora' (game_capture)
16:13:42.000: - source: 'Deathsmiles' (game_capture)
16:13:42.000: - source: 'livesplit' (window_capture)
16:13:42.000: - scene 'Jeux 16:9':
16:13:42.000: - source: 'fond' (image_source)
16:13:42.000: - source: 'chat irc' (window_capture)
16:13:42.000: - filter: 'Rogner' (crop_filter)
16:13:42.000: - filter: 'incrust' (color_key_filter)
16:13:42.000: - source: 'webcam' (dshow_input)
16:13:42.000: - source: 'twitter' (image_source)
16:13:42.000: - source: 'armello' (game_capture)
16:13:42.000: - source: 'Geometry Wars' (game_capture)
16:13:42.000: - source: 'Polynomial 2' (game_capture)
16:13:42.001: - source: 'Civ 6' (game_capture)
16:13:42.001: - source: 'minecraft' (game_capture)
16:13:42.001: - source: 'alien' (game_capture)
16:13:42.001: - scene 'Road to 92':
16:13:42.001: - source: 'stéréo mix' (wasapi_input_capture)
16:13:42.001: - source: 'fond' (image_source)
16:13:42.001: - source: 'webcam' (dshow_input)
16:13:42.001: - source: 'chat irc' (window_capture)
16:13:42.001: - filter: 'Rogner' (crop_filter)
16:13:42.001: - filter: 'incrust' (color_key_filter)
16:13:42.001: - source: 'Typhoon 2001' (game_capture)
16:13:42.001: - scene 'Gentoo':
16:13:42.001: - source: 'fond' (image_source)
16:13:42.001: - source: 'chat irc' (window_capture)
16:13:42.001: - filter: 'Rogner' (crop_filter)
16:13:42.001: - filter: 'incrust' (color_key_filter)
16:13:42.001: - source: 'webcam' (dshow_input)
16:13:42.001: - source: 'armello' (game_capture)
16:13:42.001: - source: 'ubuntu' (window_capture)
16:13:42.001: - source: 'VM-Gentoo' (window_capture)
16:13:42.001: - scene 'Beta test':
16:13:42.001: - source: 'Polynomial 2' (game_capture)
If you look at the scenes Jeux 16:9 and Jeux 4:3, you have FAR too many game capture sources in the same scene. A common misunderstanding is that you need a separate game capture source for each game, but this is not the case. Having multiple game captures in the same scene (and, IMO, more than one in a scene collection) causes conflicts. This could explain the issues that you're having. If you need to capture multiple games in the same scene, you can configure the game capture source to use "
Capture foreground window with hotkey" and then set the hotkey in Settings -> Hotkeys. This will allow you to simply press a key to capture the active window.
To see if this is truly the issue, create a new Scene Collection (not just a scene) from the menu at the top of OBS, as shown here: