The registry holds an invalid path to your Prepar3d.exe Platform manager will be unable to register SODE for P3D. Please fix your registry.
Then I get the following screen:
Platform installation path: D:\ (which I think should be D:\P3D because I installed P3D in that folder on my D drive)
First, try to understand that SODE is a freeware utility that we supply with GSX, but that doesn't mean we are supposed to support it here.
In any case, the error message from SODE is quite clear: the registry key for P3D is pointing to D:\ but, there's no Prepar3d found in that folder.
Are you SURE you installed into D:\P3D ? If yes, there's no reason why your registry key would point to D:\ but, instead, if you did some kind of mistake, and tried to install into D:\, which is really a bad practice, it's *possible* the installation of the sim didn't complete correctly.
Try to Uninstall and Reinstall the sim. Be CAREFUL and PAY ATTENTION to install it *into* a folder, NOT at the root of a drive. And pay attention if the installation of the sim gives you any error messages because, if it does, it's possible the installation was aborted, which explains why the registry keys were not set correctly.