Step to follow: - Create an Asset Models - Set up the Fixed Asset Account: Automate Asset -> Create in draft or Create and validate Asset Model -> The one you have just created - Create a Vendor bill Account -> the Fixed Asset Account of the asset model created Label -> insert a newline Price -> (do not forget to set a price) - Validate - Go to the asset automatically created - @ mention a user in the chatter Cause of the issue: The generated email subject comes from the record_name and it can contain newlines Email headers don't allow newlines and an exception is thrown here https://github.com/python/cpython/blob/60b93d9e4922eeae25052bc15909d1f4152babde/Lib/email/policy.py#L143 Solution Replace newlines by spaces in the email subject opw-2522055 closes odoo/odoo#77712 X-original-commit: ed343998d39ff91a3f73cc8012be498d32c91b2f Signed-off-by: Thibault Delavallee (tde) <tde@openerp.com>