I already got 2 muspelheim crucible seeds at very early of the game, but crucible mystic gateway did not appeared.
So I waited until the ending (I heard that after ending, ratatoskr gives special yggdrasil seeds that opens unlocked other area.) but even after ending, the crucible mystic gateway did not appear.
there are some people having same problem like me but seems solution doesn't exist

please help me!