Do you see any error in the UI or in the atlassian-confluence.log?
See if you can find more clues in your logs, so we can try to better assist you.
I will suggest you to create a support ticket at support.atlassian.com, so you can attach your complete logs and we can provide you a more assertive answer.
To better understand what's avoiding the export to be completed, can you provide us more details of the information tracked in the atlassian-confluence.log file which is inside <Confluence Home/logs> directory, so we can give you a better direction?
PS: To help you in the meantime, you can take a look at this KB article which will guide you with directions according to the issue found. :)
Hope it helps!
Do you use templates with Confluence? Take part in a remote 1-hr workshop. You'll receive USD $100 for your time! We're looking for people to participate in a remote 1-hr workshop...
Connect with like-minded Atlassian users at free events near you!Find a group
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no AUG chapters near you at the moment.Start an AUG
You're one step closer to meeting fellow Atlassian users at your local meet up. Learn more about AUGs