i cant find the crystal cave... maybe im blind xD
Ok, I checked the first two hints, these are talking about the main quest. Everything else is aimed at the optional stuff. But it's very strange to see two of these appear at the same time.
The first hint is talking about the fire essence in the dessert. This is the first step in getting Ada's sis back. In this stage, players need to go into the desert zone before the Sand Town, get to the bridge-like section and climb down the roots to find a chest. It has the crystal for the quest.
The second hint leads you to Mortimer's tower, namely to the top section where Ada confronts Desona for the first time. You'll need to examine stones at the stairs and Ada will open a half-closed portal to get up. The problem is you can't go through the mountains to reach Mortimer's tower without the fire essence tamed. Ada will simply comment that it's too cold there.
The first hint pops on main quest step 3 and while you don't have the tamed fire crystal. You didn't get Serana at this point. The second one pops up on step 15 and you already saved Serena by then. There are quite a few steps between them and you can't normally proceed with the main quest like this.
So, either you found a strange bug or used a cheat engine/save editor to screw up the game's logic. If it's the first case - I'll need all the info about what happened around the time you got the crystal from the dessert and after that. if it's the second case, can't help you. It's cool if you want to use cheats or save editors, but I can't trace all the changes players can make with this to pinpoint where they broke the logic.