@IvanDiaz
I will try to reproduce the problem. If there is a bug, it is likely that it could break the 3D view until you restart the program.

To delete a dimension line from the 3D view you must have the 3D dimension line tool enabled, move the mouse over one of the control points of the dimension line while holding CTRL+SHIFT (the cursor will display a red minus symbol), then just click to remove the line. The control points are the 2 ends of the dashed lines, and the middle of the continuous line.

The Help menu has an entry where you can find all modifier keys and use tips.