What do I do if Time Machine says "Waiting" to view a particular backup?
You can delete a backup via the sudo tmutil delete command. You'll need administrative privileges to do this:


Open Terminal
Type in sudo tmutil delete (including end space, but don't press enter yet!)
Go to Finder, open your TM Drive, and open the Backups.backupdb folder
Open your Machine
You'll need to find the folder containing the backup you want to delete.
Drag and drop the folder containing the backup you want to delete into Terminal.
Your Terminal should say sudo tmutil delete /Volumes/TM\ Drive/Backups.backupdb/Mac/2014... (backslashes are included before spaces)
Now press enter. You'll need to type you user password (it won't be displayed).