Moderator
Jan Dembowski
(@jdembowski)
Forum Moderator and Brute Squad
Try some basics first.
1 – Backup your installation. Not trying to frighten you, this is always a good first step.
http://codex.wordpress.org/WordPress_Backups
http://codex.wordpress.org/Backing_Up_Your_Database
http://codex.wordpress.org/Restoring_Your_Database_From_Backup
2 – Remove that plugin completely. Make sure the file directory is removed wp-content/plugins/post_list_widget
3 – Re-install again from the source.
http://wordpress.org/extend/plugins/post-list-widget/
If that doesn’t work, try de-activating all of your existing plugins and then re-activating just that one. This is just to see if another plugin is causing a conflict.
