if add the robots meta tag, not can add node - server closed the connection.
Сhange widget to text field - everything fine, but default value equally "0 0 0 0 0 0". Now change only widget(/admin/structure/types/manage/{type}/fields/meta_robots/widget-type) to checkboxes - everything is fine and everything works as it should be.

Comments

I'm not seeing this on my setup. Add the robots field works fine with new and existing nodes. What other tags do you have enabled (I enabled all)?

Version:7.x-2.0» 7.x-2.x-dev
Status:Active» Postponed (maintainer needs more info)

Unable to recreate this problem in a new installed drupal, probably a problem with another module compatibility.
If will have opportunity to create a same site in drupal or will free time, try to find the cause.
But. If add a node, show warning:

     Warning: explode () expects parameter 2 to be string, array given in metatags_quick_field_widget_form () (line 411 of / var/www/d7test/sites/all/modules/metatags_quick/metatags_quick.module).
     Warning: Invalid argument supplied for foreach () in form_type_checkboxes_value () (line 2233 of / var/www/d7test/includes/form.inc).

Hi, it gives me the same error when creating a new node, if only I enabled the meta tag robots checkboxes.
I hope this helps to narrow down the said issue.

Hi, same problem here with meta tag robots checkboxes.

Warning: Invalid argument supplied for foreach () in form_type_checkboxes_value...

Error message goes away, when setting a default value for robots meta field.
The weird thing: the error does NOT come back, when removing the default value setting from this field.

Tested on two different fresh D7.15 installs with hardly any modules activated.
Before setting a default value, I tried the usual flush-flush-flush cache. It didn't help.
Another thing: as soon as the robots field (of a node) has any value (not only default), the problem is gone for this node. Even after the field value gets removed again.

Is the setting saved as string (or nothing) and suddenly turns into (and stays) an array, when touched?

Issue summary:View changes

parser