I have had issues with mouse clicks not working in Grasshopper today. I am using build 1.0.0007, in Rhino 6 (6.10.18279.17351, 10/06/2018).
When this happens I can still click on things in the main Rhino workspace, but not in the grasshopper workspace. I thought at first it could be my mouse. But the buttons on my trackpad lose functionality at the same time as the mouse.
I think this issue has something to do with a boolean toggle button I am using to initiate a silkworm g-code generator. I suppose that could be because silkworm has not been updated in about 6 years. Usually when this has happened, I have had to restart Rhino entirely to get mouse click functionality back, although once it came back on it’s own.