We have received many reports of an error when exporting a character sheet. We do have the developers investigating this error but there is a fix that you can make to the character.
We have found that custom skills without ability stat chosen is causing this error. Please check your character and remove any skills like these that you might have on the character. This should make the error go away and allow you to export your character.
If this does not resolve the export issue please submit a support ticket to us on our email form.