Hi
We have one user on Confluence right now, who happens to use it the most, when trying to save a draft receives the attached error. Cache has been cleared, different browsers have been tried but still the same persistent error.

We are using Confluence 6.4.3. I was reading the collaborative issue on the listed problems for Confluence but that isn't related to this particular problem.
I am unsure what else could be causing this. I checked out the Atlassian logs but nothing is reported for this particular user in regards to drafts. Does this log somewhere else?
Regards,
Gareth