Not able to update or delete attribute option in admin

Question

I am not able to update or delete the product attribute options in admin-end.

When I am clicking "save" or "save or continue" after updating or deleting the attribute option, Magento shows me the success message that the atrribute has been saved successfully but I can still the see the deleted option in the list and also the option that I have changed is also not modified.
However, I am able to add new attributes without any issue.

The same functionality is working absolutely fine on my staging environment but creating issues on live.

What can be the probable cause of the issue and how can I fix it?

Answer 1

The issue was server related.
I have checked the server log and found below message in there.

PHP Warning:  Unknown: Input variables exceeded 1000.

So I went ahead and doubled the limit to 12000.
I tried few other values in between as well but they were not working, but 12000 work. So I have kept max_input_vars to 12000.

So, in my case the solution was to increase the value for variable max_input_vars.