CC won't install and just disappears

Hi, my mac has been to the repair shop and now i have to install Creative Cloud again, but it wont - i dobble click on the .dmg and it looks like its installing but then disappears. 

One of the advices is to go to terminale and paste the command: sudo chmod 1777 /tmp AND then type password. BUT WHICH PASSWORD?? ive tried both the CC password and my computers but nothing happened??