I am having this error when trying to send invoices via HTTP
“Invalid element ‘div’.Unexpected end of file.”
I tested the email and it was working fine
I am not using any sort of themes
I am using Manager’s public email service

I am having this error when trying to send invoices via HTTP
“Invalid element ‘div’.Unexpected end of file.”
I tested the email and it was working fine
I am not using any sort of themes
I am using Manager’s public email service

Please post a screenshot of the complete Invoice Edit page.
Create a test business in English language and try. Also note that email.manager.io is not an email service but a HTTP relay service that sends forms such as Invoices.
The div expected on end of file means you have somewhere in the Invoice added code. As you say you use standard theme I can only guess that you have created a footer with incomplete code.
I did as you said and it works fine in a test english business
and I am using Sadia Arabia version and that means it has to be fixed on other languages
Indeed, it may have to do with localization and therefore @Lubos may look into why you get the error.
It seems like this is an old problem, it happens on Invoices that use qr codes. We need to move the Qr code into the invoice table.
This works with the script on localization
but when receiving an email the QR doesn’t show, I don’t know if this related to the code or not