Grasshopper shows been blocked and unable to be load...NEED HELP!!!

As the image shows

I can't open up grasshopper in Rhino 5

says it's blocked

I followed the instruction went to the website

It says there is a "unblock" button under properties menu

but under my properties menu

there is no such thing like a "unblock" button or "advanced" button

like this:

Could any one help please?

I'll be greatly appreciated