I installed the 2018 version yesterday then late yesterday and this morning I couldn't get any exports to work within it. It would sit there with the files waiting but nothing happening.
And when quitting it would stall and once again do nothing before having to crash out of it.
Now I just discovered that I was not clicking on the 2018 icon but the 2017 icon. So just uninstalled 2017, started clicking the correct icon and it's firing through my videos perfectly.
I may just be a total idiot and be the only person in the world to have mistakenly been trying to open the wrong application. But you never know. I spend this morning trying to re-install stuff and all I had to do was look closer at what I was actually trying to launch:)