Decoration can't be finished

Dear dev. team,

This is a problem my friend is facing with his account, when he tried to finish the decoration, he can’t, the view jump to the entrance like the 2nd photo below but the decoration is not finished, so one of his worker is kept occupied. His in game name is 杰他他老伯. Could you help to look into this?

 

I think this is kind of different with the problem I saw on this forum earlier, which is due to the tower was in another defense layout or something, but now this problem is on a decoration which should not create a similar problem.

I’ve had this problem before.  For some reason the decoration ended up in my inventory.  If you go to your inventory and place all finished decorations in your city then you should be able to upgrade it.

Thx a lot for your advice, will forward to him and try.