While I playing Digimon Rury, I found a script problem while in mountain.
In mountain, you can find Dark Crystal on the top of mountain - You need a sword to break it. The sword is protected by Drimogemon, So you have to defeat it to get the sword.
However, you have to visit professor first before you get the sword. If you don't visit professor first and defeat Drimogemon, the game won't proceed.