Component panels error

I have been using GH 0.9.0014 on Rhino 4 for a while. Today when I open GH, I found that the layout of component panels has changed.

I could see components only through a category tab (for example, Params) and another drop-down list (for example, Geometry). It supposes to show most recently used items by just clicking a category tab (and show all items by clicking on the black bar at the bottom of panel). Now all components (icons) are hidden. 

I didn't do any version upgrading, neither Rhino nor GH. Does anyone know how to fix it? Thank you very much in advance.