Answer:

This error occurs when there is a misconfiguration in your app tab on Facebook, or the app server is having issues.

You can setup a backup tab using the standard iFrame App:

  1. Go to https://apps.facebook.com/iframehost/
  2. Click Add Tab to Page for the page to add it to
  3. Click Installed to view your page and click on the Welcome Tab (you may need to click More… first)
  4. In the Tab Settings displayed, select URL next to Page Source and enter the secure social commerce url. This is found in Step 4 of the Social Commerce setup tab:
    • sc-step4
    • It must start with https and end with /?obox-fb=1. Example: if our site URL is http://demo.oboxsites.com/social-commerce then our Social Commerce URL is https://demo.oboxsites.com/social-commerce/?obox-fb=1
    • woobox-tab
  5. Increase the Height in the box to the right of the URL from 800 to at least 1200.
  6. Leave all other settings default and enter your desired Tab Name
  7. Click Save Settings, then View Tab at top-right.
  8. Your shop should load without issue.
  9. To change these settings anytime, click the Settings link at top-right. Your visitors never see the Admin Options bar you see above your shop.
  10. To delete the tab, click More… on the Facebook page nav, and choose Manage Tabs

If you continue to have issues with your shop displaying in a Facebook tab, you may need to troubleshoot SSL on your site. See Social Commerce: Troubleshooting Common Issues