why .htaccess is showing me "Internal Server Error"? - php

Question

In my site I removed .php extension from the url using .htaccess rules. So that I can go to any page without .php extension. e.g :
http://localhost/aponit/dev/zones (there are no .php extension)
Now,I have a link in a php page to update a form data. Link is bellow :
<a class="btn btn-success btn-xs" href="<?php echo SITE_URL."update/$zone_id"?>" >Edit</a>
This link showing following url :
http://localhost/aponit/dev/update/54
But unfortunately It's showing me error message :
Internal Server Error
I am using following .htaccess rules :
ErrorDocument 404 /not-found.php
RewriteEngine on
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME}.php -f
RewriteRule ^(.*)$ $1.php [NC,L]
RewriteRule ^update/([0-9]+) update?z=$1 [L]

Answer 1

Trying to:
ErrorDocument 404 /not-found.php
RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^([^/]+)/$ $1.php
RewriteRule ^([^/]+)/([^/]+)/$ /$1/$2.php
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_URI} !(\.[a-zA-Z0-9]{1,5}|/)$
RewriteRule (.*)$ /$1/ [R=301,L]
And post detail log file???

Answer 2

The .htaccess code that yuo have provided will not work correctly if the site does not run under root domain. For example
RewriteRule ^update/([0-9]+) update?z=$1 [L]
This code block tells the server that any URI starting with "update" following a number will be rewritten. but in your case, the URI always starts with "aponit/dev/". So this code will not work any time.
Solution
Set up a virtual host. You will get a lot of available tutorials online how to setup a virtual host based on your server software(XAMPP/WAMP etc)
If you just want to remove .php from url, use the following code in .htaccess:
RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^([^\.]+)$ $1.php [NC,L]