Cursor not pick up edge in drawing view

Hi Guys,

Normally I should see a vertical line next to the cursor for the assistant to pick up the edge for dimension, but I don't see it since this morning. (Please see the screenshot attached) It was working fine yesterday and I haven't change any setting since then.

Is there anyone have a solution for it? And What cuase this problem?

Thanks in advance.

SolidworksDrawings And Detailing