RCTgo

If these are admission gates they can only be placed from the scenario editor. If that is where you are working, double check the install folders and docs, check that the proper files are in the proper folders; there's always the chance you have a bad download, get the file again, from a different source if possible, remove all installed files, and try again. And double check the docs yet again, it's easy to overlook some simple note when you are familiar with installing mods (I once spent an entire evening trying to get a mod to work, only to finally see another file was necessary, from a different download).