Client problem. Hidden option.

I did`t know at the beginning , why when i open the client it shows an windown with an error (it can select the lenguage, but i press ok and all works fine). When the game what to update, is shows me and unknow error , and it tells me to check error logs.

I find the problem:D If I put the game in Hidden , (Right click -> properties-> Atributes->Hidden->All files and subfolders.) i have that problem, if no... the.. no problem:)

My question is... why?