While Editing The Customer, I'm Getting This Message. How Can I Solve This.?

I found there was an issue with this method in


public function unserialize($string)
    $result = json_decode($string, true);
    if (json_last_error() !== JSON_ERROR_NONE) {
        throw new \InvalidArgumentException('Unable to unserialize value.');
    return $result;

Customer Edit Screen

Please help me out. Thanks!

  • What is stored inside the $string when error thrown? Jan 8, 2019 at 8:50
  • I have the same problem Jan 8, 2019 at 20:49
  • @SiarheyUchukhlebau, I see the same error in Magento 2.2.x, do you recall what you had to do fix this issue?
    – cnu
    Feb 25, 2020 at 3:01

3 Answers 3


I also came accross this error today, for me i discovered it was the Ebizmarts_MailChimp module that was causing the issue, you can disable the module entirely which corrected the issue or what i chose to do instead was

rename the file




which stops the ebizmarts customer edit tab loading on the customer edit screen which solves the issue for now (its not a tab i used anyway), i checked and i was using the latest version of the module.

  • Thank you. This was also my problem. Perfect Jan 13, 2019 at 20:54

The solution is simple. Update the mailchimp extension to the current version (look at https://github.com/mailchimp/mc-magento2/releases to know what version you must install) and truncate the table mailchimp_interest_group This is because the way to serialize the interest_group changes, and in the table the saved values are in the old way.



I was able to fix it by overriding one line from Ebizmarts\MailChimp\Helper\Data. You must change: $groups = $this->unserialize($interestGroup->getGroupdata()); to $groups =$interestGroup->getGroupdata();

You can do it by creating another module and inside a di.xml file override this helper.

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