Best to start a new thread. Be since we're here...
Does export fail at different points ... or are there clips missing from the completed export?
Install the latest version. If you paid to register your current copy save the installer. That version never expires. And upgrades are free for six-months after purchase. After that, what you download will be a trial that eventually may have some limitations.
Bracketing clips to select segments, then dropping them onto the timeline has no bearing on export. It should output the entire sequence.
If export completes, but clips are missing, see if the my August 5th, 2018 tip above is your answer.
If not, please upload your project. Someone will check it out. Here's how... http://nch.invisionzone.com/topic/23659-tips-for-getting-help-on-this-forum/
Don't forget to make the link public (share it), then paste it here.