Automotive Theme offset errors

The theme is supposed to be compatible with this version of WordPress (4.4) and all other things seem fine also. However it works a little like ‘Porducts’ and WooCommerce but allows publishing of ‘cars’ instead. I get tonnes of “offset errors” on the creation page when adding cars such as:

“Warning: Illegal string offset ‘car_taxonomies’ in /Applications/XAMPP/xamppfiles/htdocs/wordpress/wp-content/themes/cardealer/extensions/cardealer/views/admin/car_attributes.php on line 345”

also in settings of that plugin:

Fatal error: Cannot unset string offsets in /Applications/XAMPP/xamppfiles/htdocs/wordpress/wp-content/themes/cardealer/extensions/cardealer/classes/user.php on line 677

I tried existing solutions, changed wordpress versions around, deactivate active and (dont laugh Deployed!) thinking it will change. Still no change. Maybe its the php version? I dont know whatever it is, its irritating.

(Note: I always got an error when I was installing wordpress, something got to do with regular expression and offset is 0 or something like that. That looks closely related?)
If I need to fic that can someone send me link or any form of help how to do it because its driving me insane! 🙂