[Civi 4.5] White page on sending mailing

[ichi]

Hello, since the update to Civi 4.5 [Drupal 7] there is a white page right after submitting the mailing.
But the mailing then appears in the "Scheduled and Sent Mailing". This Mailing is not approved to run and a button "Approve/Reject" is shown.
If I try to press the button "Approve/Reject" then again a white page appears.
Of course I check the user permission. The user is allowed to  Approve any mailing.
What went wrong during the update process ?
It is a bit late to use a back-up with Civi 4.4.x because too many contact had been added in the database.
Can I fix this issue ? Thank for any help.

Best regards.

[Dan C]

My guess is you are getting an error of some sort that isn't being displayed.  Do you see anything in either your PHP error logs or in the CiviCRM error logs? (I would check the php logs first).

[yichalal]

Same issue with 4.5 and  4.5.2 here. The php error is

Code: [Select]

Fatal error: Unsupported operand types in /sites/all/modules/civicrm/CRM/Core/Form.php on line 866