Ctrl+D cannot open variable editor

Hi all,

I am using Matlab 2018b.

Previous when I use "Ctrl+D" on variables and functions. I can open them in variable editor or editor window.

But somehow now when I use "Ctrl+D", I can only open the function.

If I use "Ctrl+D" on variables, it shows "cannot find this mat file".

Does anyone know how to fix it? It's really annoying.