Wall, Ceiling and Railing Issue

[EuroDesign]

Howdy,

 

I don't know what I did wrong here.

Everything has been going great up till now.

 

This is an existing one story house, with a 2nd floor and stairway being added to it for our client.

I had this set up perfectly until we needed to change the new 2nd floor ceiling height from 9' to 8'.

 

I do not know what I did wrong, but now the wall just above the staircase is doing some really wonky things.
I've tried everything to fix it. to make it worse, it will not let me select what appears to be a section of the ceiling and maybe subfloor.

The odd stud in the middle of it is caused by the railing somehow.

 

From what I can tell, this is due to the 2nd story wall above.
Please help, thanks!

Chief Architect - Issue.pdf