Users without admin permissions get a redirect loop error when they try to create a certain (organic group content) content type, when the parent (organic group) content type does not exist.
That is, instead of getting the edit form or a 403 error, they go straight to a redirect loop error. We do not have have any 403 redirect overrides, so that's not the cause. The .htaccess file is the default one provided by the Drupal installation.
Using the "display redirection page" reveals that the add node form is redirected to the add node form in this situation. I've been unable to find any any Rule or other setting that could be causing this.
I am not using the Global Redirect module (which research indicates is the most common cause of this problem). Putting the site into maintenance mode and turning off all path, url, and indexing related modules, including Pathauto and Rules, (and reverting to the default Drupal theme) doesn't solve the problem.
The problem does not occur for anyone with the "override access permissions" privilege set.
- as to what might be causing this or
- next steps I can take trying to debug this problem?