I just installed the 2018 version SP1 . when i tried to draw, i put the line (L) command and then the left mouse button did not work, i couldnt select the points. same as dimension, offset, trim and actually most commands that require me using the left mouse button after inserting the command. on the other hand i can select a dimension line or a note and make adjustments on them. so basically the left mouse button doesnt work after inserting the commands.