Can someone please give me some detail about my issue. I am duplicating categories along with the product on my local system it works fine although it takes little more time but works fine on my live instance it gives me 404 error after completing all functionality don't know why behaving strangely.
My local Magento version is 2.2.7
live instance Magento version 2.2.7 on which it gives 404 error and remain stuck on the controller rather than returning value
live instance Magento version 2.3 on which it gives me undefined index in which I am getting value through post method and it is getting the value I double checked it
Although it completes its functionality in both live instances and then through such error at the end.