Can't save attributes on a configurable product

[bambamboole]

Preconditions

I have a Magento Installation where I can't save attributes on a configurable product. (simple products work!).

Magento Version: 2.2.2
PHP Version: 7.1.13
MySQL Version: 10.1.30-MariaDB

Steps to reproduce

1. Add a configurable product
2. Change some attributes (tested with product images and country of manufacturer)
3. Press Save

Actual Result

The following error occurs:

Warning: array_filter() expects parameter 1 to be array, string given in /var/www/dev.****.com/htdocs/web/vendor/magento/module-configurable-product/Controller/Adminhtml/Product/Initialization/Helper/Plugin/Configurable.php on line 145

Expected Result

The product should be saved normally

[magento-engcom-team]

@bambamboole , thank you for your report.
We were not able to reproduce this issue by following the steps you provided. Please provide more detailed steps to reproduce or try to reproduce this issue on a clean installation or latest release.

[magento-engcom-team]

@bambamboole, we are closing this issue due to inactivity. If you'd like to update it, please reopen the issue.

[davygxyz]

@bambamboole Did you ever get this figure out? Getting same error. Magento 2.2.1

[bambamboole]

@davygxyz Yeah it was a problem with the Web Application Firewall in Azure. After some research I saw an Ajax Request which responded with a 403 nginx page. After that it was clear it is no problem with magento but with the setup.

[davygxyz]

@bambamboole Nice! thanks for leading me in the right direction. I've been stuck on it for a day, so this helps.

[ctadlock]

This issue happens when one of the attributes of the products is required.

[A-1A]

I Found Solution after R&D On Magento database.
Login In your phpmyadmin
Go to your website database
Open "eav_attribute" table
Find Your multiselect "attribute_id"
Edit Row
If "backend_model" Column blank then paste this Magento\Eav\Model\Entity\Attribute\Backend\ArrayBackend
And also please check
https://magento.stackexchange.com/questions/224621/warning-array-filter-expects-parameter-1-to-be-array/230444#230444

[magento-engcom-team]

Hi @bambamboole. Thank you for your report.
The issue has been fixed in #16597 by @swnsma in 2.2-develop branch
Related commit(s):

• d866b18757ca50bc97df4038a874a4bddf465a4c
• bc00d8e059ba168694962249d09cd82f99e9ef46

The fix will be available with the upcoming 2.2.7 release.