Hi,
I want to customize the 404 error page via Jsitemap but I have a strange problem.
I'm using Joomla 3.5.1 and protostar template.
When I had an old template (not responsive) I had made a custom 404 error page via an article in a Hidden menu and Joomla used that article as custom 404 error page.

Now with the protostar template, I read that in folder protostar there is a file error.php that joomla using this instead of system/error.php.

I modified the protostar/error.php file with a simple text via FTP and when I wrote an invalid URL then this 404 error page displayed correctly with the text I had wrote in protostar/error.php.

So now when I go to Jsitemap Configuration/General preferences/404 page and I'm trying to create there an HTML or a simple text 404 page but it still continues to display the previous text I created in protostar/error.php and not the custom 404 error page I made in Jsitemap.

The selections I made in Jsitemap/404 error page are these :

Custom 404 page contents ------> YES
404 page override mode ------> YES
Custom contents type ------> BOTH (I tried HTML and TEXT)
Custom contents ------> I tried HTML and simple text)


Now I tried to delete via FTP the protostar/error.php but when I wrote an invalid URL then the default Joomla 404 error page was displayed and again not the Jsitemap 404 page I created. I also tried the old way I found in Google with a custom article in a hidden menu but also it dosen't work!

Can you advise me to do something, or am I do something wrong?

Thank you!