Haha! I managed to get the videos to play using the following workaround:
- Locate your game files (usually at
C:\Program Files (x86)\Steam\steamapps\common\AoE2DE
). - Right-click on AoE2DE_s.exe and select Properties.
- Go to the Compatibility tab and enable Disable Fullscreen Optimizations.
- Click Apply and then restart Age of Empires II.
I’m not entirely sure what this setting does, but can you check if the videos play for you with it enabled?