Magento2: M2.1 "Invalid Form Key" when saving configurable product with multiple configurations

[5zymon]

When I try to create or edit configurable product that has multiple simple products in configurations, Magento returns "Invalid Form Key. Please refresh the page." error. Of course refreshing the page, clearing cookies, cache, nothing works. When I limit number of configurations to a lot less (for example 4) same form comes trough just fine. This issue was not present on 2.0.7 I was able to save configurable products with multiple configurations.

[5zymon]

The solution is to increase max_input_vars in php.ini file. not a Magento 2 issue.

[SewHappy58]

I tried increasing PHP input to 7500 and it still doesn't work in Magento 2.1

[bpgkt]

use php_value[max_input_vars] = 10000
instead of max_input_vars

[jpcsguru]

This does not work

[ricardowong]

max_input_vars on php.ini worked for me on Magento 2.1.6

[miteshdhaduk]

It does not work in Magento2.2.2

[neilgreene]

Magento 2.2.3 and I have tried increasing max_input_vars in php.ini, I have cleared var/cache, browser cache, Magento cache, verified that for my magento.conf and magento-ssl.conf that both are using the same domain, removed domain cookies. Still, get the error when trying to edit an existing product. But, I can create new products without any issue.

Will to share hitting my head on the wall if anyone is interested.