Possible issues after updating from Magento 2.1.X to Magento 2.2?

Question

If I will upgrade Magento 2.1.0 to Magento 2.2 then is there any possible issues which I have to take care after upgrade process?

Will site work smoother or do I have to compromise with some functionality?

Any help will be appreciated.

Answer 1

You may have Undefined offset error after upgrading. You can check such issue here in github https://github.com/magento/magento2/issues/11412

Answer 2

I had issues with custom extension which was using custom tables with serialized fields

In Magento 2.1 default php serialize function is used.

In Magento 2.2 json serialize is used and trying to unserialize old entites will end up with error

Error: Unable to unserialize value.

You need to check your custom modules if you are extending default Magento functionalities or overriding classes using <preference>

Magento official guide to convert serialized data to 2.2 Thanks to @Swapnil Tatkondawar https://devdocs.magento.com/guides/v2.2/ext-best-practices/tutorials/serialized-to-json-data-upgrade.html

Answer 3

Here's a list of backward-incompatible changes in 2.2.0 from DevDocs.