Cannot Save In Admin

Hello Forum,

I am running on version 4.2.3 and when I go to Manage Stores and select a store and then make changes and hit “save”, the page loads and returns a blank screen with the default URL like this:

www.(domainname.com)/admin.php. and that is it. Nothing saves!

Any one know what is missing or what is wrong and share the fix?



Thanks in advance