Reported: Some maps cannot be entered even with the required access item. The Novajan Fortress entrance refuses with "Moving Portal Failed: The Portal Index is Wrong" while carrying a Cold Mind Stone.
Found: Novajan Fortress is part of Wounded Land, a map added in RF Online 1.5. The 1.5 client has an Outcasts' Land portal to Wounded Land. The server does not have that map yet, so it has no record of that portal and refuses it as unknown. That is the message you saw. The Cold Mind Stone check is never reached.
The log line in the report comes from a different portal in Outcasts' Land, the one to the Dimension of the Unknown. That portal asks for a Piece of Mystery, not a Cold Mind Stone. That item exists in 1.5, but no shop, monster drop or quest in the 1.5 game data gives it.
Planned fix: We will add Wounded Land to the server, starting with the Outcasts' Land entrance that takes a Cold Mind Stone. The 1.5 files we work from have no layout, monster or portal data for the maps that are new in 1.5, so this is larger work than a usual fix. We will also decide which item the Dimension portals should ask for in 1.5, since nothing in the 1.5 game data gives any of the pieces they ask for.
Also affected: The 1.5 client knows 68 maps and the server has 31. None of the maps beyond those 31 can be entered yet.