I have the problem since I have more than 6 Members to choose from. In my Case since I've met "Hiravias". I am not able to swap party members because seemingly no matter which strategy I am using to, the character which is supposed the be there is not; The castle dialog menu to assign shows everything is alright, but the in game member slot stays empty, no visible character, no portrait, no message in the console that a new party member has joined Swapping characters back does not help either, the because no member I choose appears as a 6th member from now on. So It is essentially not possible to change the party. I've tried one thing that worked for the first time: Loasing a savegame before the bug event, returning to the castle, dismissed Kana, then went out to meet the new party Member and let it join during the first dialog. Then I went back to the castle and swapping worked. BUT only until my next journey into the underlying dungeon. As I returned from the dungeon to the catle and tried to swap the members, the bug was there again and it seems if the bug appears for the first time it is permanent and the party slot is "lost" for reassignments.. This is a bug that has a huge impact on the game play and I read some posts that I am not the only one who suffers from it. Please do something about it.