I am trying to automate parts of my event business so that emails are sent leading up to the day of the event. Using Dynamic placeholders in the email template, I am trying to pick up specific data for that client from custom properties in the CRM. For some reason, this is causing an error every time. 

Has anyone had any experience with this and found a solution?

In my CRM I have created the following property fields:

Name Of Child:
Birthday:
Venue:
Type of event: 

etc

I created a campaign to email all clients that booked an event with us based on the selected activity type. I add an email to the workflow to be sent. The above date has been added to this email as a dynamic placeholder.

The following error comes up when I try to test the campaign (Please note that I am on the standard Odoo environment):

ERROR - Exception in mass mailing: Failed to render QWeb template:

Dear  Details below:

Traceback (most recent call last): File "/home/odoo/src/odoo/saas-17.2/odoo/addons/base/models/ir_qweb.py", line 776, in _generate_code raise QWebException("Error when compiling xml template", odoo.addons.base.models.ir_qweb.QWebException: Error when compiling xml template SyntaxError: invalid decimal literal (<>, line 1) Template: <Element div at 0x7f8eff102020> Path: /div/table/tbody/tr/td/div/table/tbody/tr/td/div/div/p[5]/t Node: <t t-out="object.lead_properties.3120824944bbcb08 or '''Name Of Child'''" style="font-family:Arial, 'Helvetica Neue', Helvetica, sans-serif;box-sizing:border-box;"/> )