Odoo is the world's easiest all-in-one management software.
It includes hundreds of business apps:
I described this error on my blog: \https://agipme.fr/2017/02/odoo-9-ce-error-qweb2-templatemail-chatthread-message-no-enumerator-given-to-foreach.html
I have not enough Karma to close this question :-(
Some mail record is not initialized correctly because the error disappears after deleting the messages. Could not find a proper solution here.
1. Use the live chat to ask your questions.
2. The operator answers within a few minutes.
I reinstalled the server (Debian 8.6 + Odoo 9 CE) => no more error !!
You killed a Drone with a Patriot. Really effective but not in my case.. I have several instances.