I received this error message when trying to delete plug-ins from my site:
High-five for clearing out unnecessary plugins! If you’ve encountered this error message, don’t give up. Instead, check the following:
1: De-activate First
You cannot delete a plug-in or theme while it is active. Make sure you de-activate the plugin and then try to delete it.
2: Old Theme?
Occasionally a plugin loaded under a previous theme will contain lingering code or data that prohibits you from deleting it after you’ve changed themes. Load previous theme by going to Appearance > Themes and then try deleting the plug-in. Once you’re done just re-active Acabado. All your settings will have remained intact.
3: Try Again Later
Sometimes servers just get jammed up. If you experience this error more than once, you may try leaving it for a day and trying again.