I need help to find my Media inside Folder

Hello, i have big problem with my Drobo 5D

I have some folders when I try to open it after this I have problems:
1- I can’t see any media or folders inside it
2- some folders like folder no1 I can see it normal but after i opened this folders (folders with problem) then I comeback again to folder no1 then its like the problem agin start I can see any things inside it

this is the link for the problem I uploaded it by youtube to look at it :

my system : Mac Os X 10.9.5