Make sure you actually have the latest version/patch of FH.
Also make sure that the map creator made the map/exports for the most recent version.
Look so you placed/and that you got all the files needed that should be inside the "exports" folder.
This might be some new bug I havn't seen, but it should be working. Since you get no errors and just a missing portal, then you could just try to reinstall the game. But it should be working if your game is up to date, the map creators game is, and that they actually made a working portal/you installed it correctly.