Fatal error: Unsupported operand types in /home/../public_html/modules/field/field.info.class.inc on line 479

Fatal error: Unsupported operand types in /home/../public_html/modules/field/field.info.class.inc on line 479

I got this error immediately after enabling Invite module 7.x-4.0-beta2. I previously had 7.x-2.1-beta2 but i had uninstalled it completely first as there was nothing about an upgrade path being available.
When i enabled the 7.x-4.0-beta2 version, i chose all 3 including user_relationship invite checkboxes. I have tried replacing with the dev version. This error only comes up when running update.php script, all other pages show a white screen (WSOD). I have disabled all invite related modules in the database to no avail.

This is what is at line 479:
public function prepareField($field) {
// Make sure all expected field settings are present.
$field['settings'] += field_info_field_settings($field['type']); <--line 479
$field['storage']['settings'] += field_info_storage_settings($field['storage']['type']);

Please help i'm really at ends here.

**Update. Had commented the line till i got the site back up. But it occurs everytime i re-enable. Got access to logs below:
Notice: Undefined index: field_invitation_email_subject in invite_by_email_form_invite_form_alter() (line 404 of /home/.../public_html/sites/all/modules/invite/modules/invite_by_email/invite_by_email.module).

and

Notice: Undefined index: max_length in text_field_widget_form() (line 512 of /home/.../public_html/modules/field/modules/text/text.module).

Using EntityAPI 7.x-1.6 and CTools 7.x-1.6+3-dev i can't seem to reproduce this on my test site though.