subscribe2 plugin not auto sending v8.9

Question

v8.9 Subscribe2 plugin is not auto sending emails when a new post is created.

this is the error from the logs...

Subscribe2 has an error in the logs: (/var/www/vhosts/iglobal.amese.co.uk/statistics/logs): view /var/www/vhosts/Cloud2.mydomain.co.uk/subdomains/folder/iglobal/wp-content/plugins/subscribe2/classes/class-s2-core.php +432

i was also told by my hosting company that there was a null value for the email type, as in the whether the email is html or plain text and that value was not being stored.

the website is currently on a dev area on a sub domain. i've tested the auto-post with an email at the domain where the subdomain is and i tested it with my gmail email.

what i've done to DEBUG...

1. installed email log plugin
2. rolled back to version 8.8 and have same problem.
3. deactivated every single other plugin and tried to resend.
4. spoke to my hosting company who gave me the error log
5. checked the version number against a know working plugin on another WordPress site i have installed and that works.
6. experimented with 0 and 1 recipients with settings.
7. experimented with other settings with subscribe2 including html and plain text.
8. made sure no categories were excluded.
9. uninstalled the plugin and reinstalled it.
10. did some kind of mad chicken dance before i pulled my hair out.

does anyone have a magic wond? :(