I do not have Rise of the Rajas installed, but I can guess that the base game itself was updated on steam so it doesn't really matter if I have the DLC or not. I cannot convert the game assets:

converting from '/home/kevin/.steam/steamapps/common/Age2HD'
WARN [py] You have installed incompatible game version(s):
WARN [py]  * Age of Empires 2: HD + Rise of the Rajas (Version 5.x)
WARN [py] You need at least one of:
WARN [py]  * Age of Empires 2: The Conquerors
WARN [py]  * Age of Empires 2: The Conquerors, Patch 1.0c
WARN [py]  * Age of Empires 2: Forgotten Empires
WARN [py]  * Age of Empires 2: HD Edition (Version 3.0+)
WARN [py]  * Age of Empires 2: HD + Forgotten Empires (Version 4.0+)
WARN [py]  * Age of Empires 2: HD + African Kingdoms (Version 4.7+)
 ERR [py] game asset conversion failed

I understand that this is a duplicate of #788 . What I want to know is:

1. Is there a workaround? Can I "downgrade" the steam version or something just so that I can get open age to work?
2. Is a fix already under development? Curious because all new potential users/contributors would run into this issue if they are using the steam version
3. I can help with the fix, but I have no idea where to start. Where do I start?
4. Or maybe the problem is that the script is misdiagnosing my version (as the rise of rajas) while what I actually have is a perfectly compatible game. In that case we can simply fix the GameVersion enum.