It's the 3rd time this has happened to me now. I fall through the floor while grinding, I end up in the ocean and the mobs still follow me down there and kill me?? Lost yet another crystal to this. 

For the love of god PLEASE fix this. I just want to grind in peace without having to worry about FALLING THROUGH THE DAMN FLOOR. 

Falling through the floor has happened to me in a variety of different grindspots, from Elvia Hexe, to Dehkia Sulfur, to City of the Dead among others, when it happens I have been making reports to support. Ask for your crystals to be restored, since you lost them to this bug. Whenever I have discussed this with support, they have asked me if I lost crystals to the issue, so they may well be willing to restore you the crystals. If enough people report when it happens to them it will make it obvious to PA how widespread this problem is.

Fortunetely, in the grindzones where I have fallen, the water is deep enough below the ground that I have fallen to my death before the enemies were able to kill me, which avoids crystal loss. Ideally, the game should detect when a character is in an abnormal location and teleport them to a normal location. Until PA fixes this major issue, I recommend force-disconnecting yourself before the enemies can follow you into the water and kill you, then either use the character transport function to move yourself to a safe location or (if this is impossible) log into your character during node wars on a node war server (which will make the enemies be absent) then use escape-escape to get out of the water hazard.

My condolences for you having to deal with the problem repeatedly, PA should act decisively to correct this; crystal breakage is absent on console, and given the existence of this kind of problem, PA should remove crystal breakage from PC as well.