PS Bug: cannot use eyedropper tool 無法使用滴管工具，因為程式錯誤。

無法使用滴管工具，因為程式錯誤。

I wanna add gradient to the shape, so I open the layer effects window. As I use eyedropper tool to create the gradient, this window pop up saying "the eyedropper tool is unavailable due to a programming error".

Below the sentence there are two options, left one is "Understand how to fix/resolve.", but "Sorry, we couldn’t find that page." showed up after clicking it.

The eyedropper tool is completely fine until I get to the “layer effects” window, the problem also appears as I double click the shape layer, then try to use eyedropper tool to pick color. 

Please, anyone know how to fix it, much appreciated.