Magento 2 error while adding new order status

Question

I went under Stores -> Order Status -> Create New Status, and when inputting a Stautus Code and Status Label, I get the following error:

Warning: Invalid argument supplied for foreach() in /home/fendow/public_html/vendor/magento/module-sales/Controller/Adminhtml/Order/Status/Save.php on line 32

Can someone please give me a hint as to what the reason for this might be?

Answer 1

This error will only happen when in Single-Store Mode.

1. Switch out by going to Stores > Configuration > General and setting "Enable Single-Store Mode" to "No".
2. Create your new status and assign to an order state.
3. Go back and set "Enable Single-Store Mode" to "Yes".