After upgrade have this error
Call to undefined method Mage_Core_Model_Email_Template_Filter::setTemplateProcessor() in app/code/core/Mage/Core/Model/Email/Template.php on line 305, referer: http://DOMAIN/sendfriend/product/send/id/929/cat_id/199/
I have the same error when trying to create new account, in url : /customer/account/createpost/
Could you please tell me exactly how you've done? I hope not going to a blank reinstall.
I'm having the same issue. Re-installing didn't solve. It happens when I do things that should generate emails. So forgot password will work if the email entered doesn't exist in the database. But if it does, and it's supposed to send, it makes the error described.
I tried making a new Email Template in the backend by just selecting the default forgot password and then making no changes. I tried re-installing everything. Still having this issue.
FYI: We had recently gone from 1.6 to 1.9. We've installed all patches, everything said it was good and the site generally works. Just not things that send out emails.
I'd be grateful to hear from some others on this.