I installed LR6 from a DVD. Then proceeded to do an update from the "Help" menu. By all appearances the update seemed to be progressing as it should, but apparently was not successful as the tethered function did not work. Shut the laptop down and came back later and tried the update function again and this time all was good and I could see that it worked because halfway into the LR6 update it asked to have the LR app closed so the update could proceed. After this attempt the tethered function work perfectly and LR was updated to 6.5.