First you should check if the game controller is detected by Windows at all. For example, if you have a Logitech steering wheel, open the Logitech Profiler and see if the steering wheel is recognized and works. If this is the case, start the 32-bit version (!) of LOTUS and see if the controller is recognized there (rename LOTUS.exe to LOTUS_64.exe and LOTUS_32.exe to LOTUS.exe and then start LOTUS as usual).
If a controller has been detected, a window should appear which also shows that a new controller has been found (only the first time!)
If this window doesn't appear and the small controller in the lower right corner of the main menu remains black just go to the options and try to add a controller key to an event under key bindings (just select an event and click on "Add"), if this worked the controller should now have a green dot .
If the controller has a yellow dot you have to activate the option "Game Controller / Joystick on" in the options under General.
If all this works in the 32-bit version but not in the 64-bit version, it is because the LOTUS_input.exe1 was found to be harmful by your anti-virus program and is therefore not executed in the 64-bit version. To fix this you have to add LOTUS_input.exe1 to the whitelist of your anti-virus program.