NOTE: As of Medieval Dynasty v1.5+, the DLL is not enough on its own to restore the Cheat Menu.
A YT video detailing the updated instructions, involving extracting files from an old game version to mix with the new version can be viewed here - https://www.youtube.com/watch?v=06n0JKxKDGk
DLL to restore the ingame cheat menu.
Steam will want xinput1_3.dll, MS Store version will want xinput1_4.dll.
When launching the game with the DLL in place a black console window should appear. If you do not see this window, the game likely failed to find the DLL.
For the MS Store version, drop xinput1_4.dll in the folder: C:\XboxGames\Medieval Dynasty\Content
For the Steam version, drop xinput1_3.dll in the folder: ....Wherever Steam wants it. Let me know where works and I'll update this.
NOTE: For Steam/GOG do not drop xinput1_3.dll in the folder with the Medieval_Dynasty.exe, it should go in the subfolder "Medieval_Dynasty\Binaries\Win64" alongside Medieval_Dynasty-Win64-Shipping.exe.