I have a similar problem to this and this issues, a redirect loop occurs on coming back from the payment system after making a contribution.
The difference with the 2 previous links is that the problem :
- does not occur every time for logged out users
- does not occur for logged in users
- occurs only on a "second" contribution page. The main contribution page works fine.
When it's not working, the return URL is like this : /?page=CiviCRM&q=civicrm/contribute/transact&
instead of having the other get attributes like the contribution ID and such.
This site is using WP Rocket as caching plugin. I added exceptions for the contribution pages' URLs to avoid caching problems, but the problem persists and I do not know how to debug this issue... Especially that it seems to be randomly happening...
The payment system is Ogone. CiviCRM version : 4.6 WP version 4.8
Any suggestion appreciated!