I couldn't get higher box in game

[I couldn't get higher box in game]

18 minutes ago, nakuru2 said:

its the event inventory man not the normal one, where u have the boxes u must have 4x4 boxex empty!

Thank you very much. I have received

[I couldn't get higher box in game]

I tried to get the item but still got the error checking the item box. Even though my inventory is empty. As attached picture
I hope you can check it for me, please.