Can't send order emails

[andrew6x6]

[2020-09-03 13:52:58] report.CRITICAL: Recoverable Error: Object of class Magento\Sales\Model\Order\Interceptor could not be converted to string in vendor/magento/framework/Escaper.php on line 78 {"exception":"[object] (Exception(code: 0): Recoverable Error: Object of class Magento\Sales\Model\Order\Interceptor could not be converted to string in /var/www/vendor/magento/framework/Escaper.php on

error thrown in the TransportBuilderPlugin when using the filters, specifically encountering {{var order}} variable here:
$params['params'][$label] = $filer->filter($v['value']);

Another issue is that the default order email template must be selected otherwise the order email is skipped. this stops us from modifying the template to remove the order variable causing the error.

Mapp\Connect\Helper\Data::templateIdToConfig will return 0 and the plugin will be skipped.

Magento version: 2.3.5-p1

[mappconnect]

Please check the documentation -emails templates needs to be created on Mapp Engage as prepared messages using https://documentation.mapp.com/1.0/en/use-magento-transactional-emails-7236955.html

[andrew6x6]

What about the main issue?

[mappconnect]

When this error occurred? Are the messages and mappings set properly?

[andrew6x6]

All mappings are correct. The issue is when sending the order email(s).

[mappconnect]

Email templates for the order also need to be created on Mapp Engage, additional items as parameters to transaction subtype mapping. If you represent customer Creed we don't see any prepared messages in your system.

[andrew6x6]

This bug occurs even before the email is attempted to send so I don't think that is relevant to this issue.
Have you tested the extension with 2.3.5-p1?

[andrew6x6]

The issue could well be due to the way email templates have changed since version 2.3.4

https://devdocs.magento.com/guides/v2.4/frontend-dev-guide/templates/template-email-migration.html

the order object is not scalar and causes issues.

[mappconnect]

Thanks, we were updating multistore issue and will create a plugin for newer versions with updated variables.