The PDF couldn't be attached
You need permission to add attachments to the page you export from. Ask a space admin, or export from a page where you can add attachments.
The export ran out of time or is too large
Export fewer pages (use Choose pages… or labels), or use smaller images. PDF/A exports are limited to 250 pages.
Some images or pages are missing
The finished dialog lists anything left out: images that were too large, and pages that were deleted, are drafts, or that you can't view.
I can't see Manage templates
Templates, brand and the Export API are for Confluence administrators only.
The render service could not be reached
Try again in a few minutes. Admins can check Render service on the admin page. If it says it isn't reachable, contact support@fortimus.co.