I am getting 'Unable to unserialize value' while editing a customer in magento 2.2

Question

I did data migration from Magento 1.9 to Magento 2.2 and now I am unable to edit a customer. I am getting this on customer edit page in admin side.

I tried this but it didn't work for me.

I added magento_umask in Magento root directory with number 002 but it didn't work either

Answer 1

It was a 3rd party extension issue I found this solution helpful.

https://magento.stackexchange.com/a/257393/70848

Answer 2

Run this query in your database :

select * from `customer_eav_attribute` where (`validate_rules` ='');

and if it shows any result , fixed it with this

UPDATE `customer_eav_attribute` SET validate_rules='[]' where (`validate_rules` ='');

CR from link