Problem with Mt. Lanthanite entrance

So I am having trouble entering the vertical facing cave entrances of Mt. Lanthanite. Just to give a brief description; From Silverport Town you go up the stairs and enter the cave(the entrance is horizontal from the inside). I can walk, run, or ride anywhere while inside (on water, rocks, walls, and ice w/o sliding). However, I am unable to enter the doorway at the northwest corner of the map. Leaving the cave through the east entrance (horizontal) I go east and find a bridge. Trying to cross the bridge makes it look like I am under the it, however, I am still constricted by the sides of said bridge. Trying to enter Mt. Lanthanite is seeming to be impossible. I don't know what could have caused this but it is puzzling. I currently have V4.2.3b. Also error boxes pop up when I open the game but they don't stop me from playing the game... Any Ideas?

Yeah I don't think they've made that part of the game yet, you have to go right from the steps and head towards the 7th gym instead

Yeah they say that there's supposed to be a legendary in the future, and it's not in the game yet.