If you have just upgraded your WordPress from previous version to WordPress 2.5, you can now make a Archive page to display Tags in any order, without any extra plugin requirement or in one other case, you might be using Ultimate Tag Warrior Plugin in your previous version of WordPress to generate Tags and display list of Tags in a separate page (like in TechCrunch’s Company Index or IndianWeb2 List of Companies ).

After upgrading my WordPress to WordPress 2.5 I got error for my Tag Archive page i.e. for any Tag it was showing ‘Page not found’ or some PHP error for UTM plugin function, the clarification - UTM doesn’t work in WordPress 2.5 as the latest version of WordPress has Tag functionality built in itself, the soultion for all this lies in WordPress itself.

To make Tag Archive page go for following steps, whether you were using UTM plugin or not and without any extra plugin;

1. If you were using UTM plugin previously, go to Manage -> Import and Import tags from UTM to your WordPress 2.5 database by selecting Ultimate Tag Warrior from the list (there are 4 easy Steps rest is done by WordPress itself). (skip this Step if you dont have UTM plugin)



2. Make a Page and name it - Tag.php and put it in you template folder where all other pages like archive.php, index.php lies.
3. Put these lines (just copy paste) in Tag.php page (through Design -> Theme Editor -> Select -’Tag.PHP’);

<?php
/*
Template Name: Tag Archive
*/
?>

<?php get_header(); ?> /*—Get the Header of Page—*/

/*---  Below is code for getting Tags in list Format---*/
<?php wp_tag_cloud(‘smallest=11&largest=11&number=0&orderby=name
&format=list‘); ?>

 <?php get_footer(); ?>/*—- Get Footer of Page*/

4. Go to Write -> Pages ->, Now make a fresh New Page with no content in it, select Title of your Tag Archive page, important thing is there in “Page Template” option Select “Tag Archive” as a Template of this Page.
5. Done -> publish the Page.

You can customize the tags thru function - <?php wp_tag_cloud()?>, like how they should appear in page in Tag Cloud format or List format or order of tags in order of Name (alphabetically or no. post of that tag). For example, in above I have used - &orderby=name, to order the list oaf Tags Alphabetically and &Format=List so as to display them in Listed one after the other wit line break rather than Tag Cloud wormat. For more easy customization options of refer here , Wp_Tag_Cloud Tag