Fatal Error: Taxonomy file

I’m just causing myself all kinds of opportunities for learning today. The most recent involves the following error:

Fatal error: Cannot redeclare is_taxonomy() (previously declared in /home/content/j/a/c/hosting/html/yoursite.COM/wp-includes/deprecated.php:2528) in /home/content/j/a/c/hosting/html/yoursite.COM/wp-includes/taxonomy.php on line 103

I received this friendly little message after updating Disquis.

So if you are receiving this… REMEMBER:

When updating a plugin, DEACTIVATE the plugin prior to launching your FTP software to overwrite the files OR just delete the specific plugin’s folder vs. overwriting it.

When you update WordPress, always DELETE everything EXCEPT your .htaccess, wp-config.php and wp-content folder. THEN upload the files in the zip that you have downloaded and run upgrade.php.

IF you’ve already made this mistake.. (Like me).

Then you can try a few things:

Delete the plugin
-Reset the plugins
Find the specific error in the Taxonomy file (ya, right that thing is super long!)
Switch to the default theme:
- Renaming your current theme’s folder using FTP (or use whatever file management application your host provides)- resetting the plugins folder by FTP or phpMyAdmin.

- re-running the upgrade manually.

- reviewing http://wordpress.org/support/topic/411649
Re-write the Taxonomy file
http://plugins.trac.wordpress.org/browser/custom-taxonomies/trunk/custom-taxonomies.php?rev=95735#L62. Add a line before line 62 that says:
```
function custax_register_on_init() {
```
Then after line 70, add this:
```
} // end custax_register_on_init()
add_action( 'init', 'custax_register_on_init' );
```
Try a Taxonomy plugin patch:
apply this patch, then aim to switch out this old plugin with a newer one (perhaps one you write) at a later time, before you need to upgrade again.
More tips: http://nerdlife.net/custom-taxonomies/#comment-3206
Cry yourself to sleep. Then hire Agency Couture to fix the problem.