Issue Summary

Customer portal users are not able to perform PDF export.

Steps to Reproduce

1. Have a Confluence + JSM environment
2. As a SITE-ADMIN:
   1. On JIRA:
      1. create a Service Project
      2. create a new space or link an existing one as a Knowledge base
         1. On Knowledge base settings:
            1. Who can view: All logged-in users
            2. Who can edit: Only Confluence Users
      3. Go to the customers' page (left menu) and invite an account there
   2. On admin.atlassian.com:
      1. invite the same account from step 2.1.3 here
      2. revoke any product access (leave only Has access on site toggled)
   3. On Confluence:
      1. Go to Confluence Global Permissions > Anonymous users > Use Confluence (make sure it is DISABLED)
      2. Go to the space you created/linked in step 2.1.2
      3. Access Space Settings > Space Permissions > Anonymous Access (make sure all is DISABLED)
      4. Copy the URL of any page on this space
3. As a customer portal (authenticated user):
   1. Open an incognito/inprivate tab
   2. Paste the URL copied in step 2.3.4
   3. Login with the account you invited on step 2.1.3 (same as 2.2.1)
   4. Go to More Actions > Export > Export to PDF

Expected Results

The system should allow the user to perform the page export.

Actual Results

The system will show an error.

Workaround

Option #1: You can use the Word export instead: Go to More Actions > Export > Export to Word

Option #2: You can enable Anonymous access on site: Go to Confluence Global Permissions > Anonymous users > Use Confluence > ENABLED
 You can keep Space Permisssions > Anonyous Access DISABLED.