Magento 2 Redirects to Cart page after Place Order

A full theme package you buy from marketplace it commonly included: SQL file, Theme

When you install a Magento 2 by importing database from SQL file, you may get the problem related payment method.

That's your website redirected (Status 302) to Cart page after Place Order instead of Success page. i experienced with Smartwave, Plazetheme ...

How to fix this problem:

- Clear your cache by manually deleting the content of /var/cache/ folder , the /var/page-cache/ folder.

- Remove /var/generation/

- Remove /generated/ if you are using Magento 2.2.0

- Reindex your website by using the SSH command line php bin/magento indexer:reindex

- Deploy again the theme by ysubg the SSH command line php bin/magento setup:static-content:deploy

In case you already did all the steps above but the problem is still not resolved, you can use command line composer update to fixed your core Magento 2