How to enable Text formats after disabling it in Drupal?
This looks like a bug in Drupal. Anyway the following method works.


Go to your Drupal database (I use phpMyAdmin)
Browse table called 'filter_format'
There You can see list of input formats.  In  'status' column  change
(update) status form 0 to 1. (Disabled status will have 0. So
change to 1 to enable)
Clear your cache. (configuration &gt;&gt; development &gt;&gt; performance)


That's it. Now  all 'Text formats' will be visible under that configuration page.

It works, I tested it :)