We're on civicrm 4.7.5 on Drupal 7.
All contributions paid through the paypal standard payment processor are failing to successfully complete.
The user sees a successful transaction, but the contribution status is " Pending (Incomplete Transaction)"
There is nothing in the CiviCRM log to suggest an error. The IPN is sent to the correct URL, the status recorded in paypal is HTTP 200 OK.
But when I copy the path into a browser:
this prints the following message to screen:
Sorry, can not load CMS user account.
Any help debugging would be greatfully received!