I've the next during my .htacccess file:

RewriteBase /
ErrorDocument 404 /404.php
Options +FollowSymlinks
RewriteEngine on
RewriteRule ^news/([a-zA-Z]+)/([0-9]+)-([a-zA-Z]+) /news/view-article.php?category=$1&id=$2&title=$3 [NC]
RewriteRule ^news/most-viewed/([a-zA-Z]+)/([0-9]+)-([a-zA-Z]+) /news/view-article.php?category=$1&id=$2&title=$3 [NC]

RewriteRule ^news/categories/([a-zA-Z]+) /news/categories/view-category.php?category=$1 [NC]

Everything works aside from the final rule. I've checked that the web pages exist, the recently added rule follows exactly the same structure because the rules above which work, confused.

Perform the variables need altering? Shall We Be Held missing some code?

RESOLVED:

RewriteBase /
ErrorDocument 404 /404.php
Options +FollowSymlinks
RewriteEngine on
RewriteRule ^news/categories/?$ /news/categories.php [NC]
RewriteRule ^news/most-viewed/?$ /news/most-viewed.php [NC]

RewriteRule ^news/categories/([a-zA-Z]+)/?$ /news/view-category.php?category=$1 [NC]


RewriteRule ^news/categories/([a-zA-Z]+)/([0-9]+)-([a-zA-Z]+) /news/view-article.php?category=$1&id=$2&title=$3 [NC]

I had been missing the $ around the finish.

Do this, and tell me in the event that works

RewriteBase /
ErrorDocument 404 /404.php
Options +FollowSymlinks
RewriteEngine on
RewriteRule ^news/([a-zA-Z]+)/([0-9]+)-([a-zA-Z]+)/?$ /news/view-article.php?category=$1&id=$2&title=$3 [NC,L]
RewriteRule ^news/most\-viewed/([a-zA-Z]+)/([0-9]+)-([a-zA-Z]+)/?$ /news/view-article.php?category=$1&id=$2&title=$3 [NC,L]
RewriteRule ^news/categories/([a-zA-Z]+)/?$ /news/categories/view-category.php?category=$1 [NC,L]