Cannot click unit and make them move

(my english skill is very bad, plz consider about it)

i played chapter 6, i pressed E button to select all unit. and i want to move spartan foward, i clicked 1 spartan unit.

then right/left click didnt work. i cant pick other units, i cant move my unit.

E, Q keys are worked, but i cant move to anywhere. because there is no button moving units without mouse left/right button.

why did it happen? i want to know how to fix it