SSH won't start: bad configuration options

Symptoms

When attempting to start SSHD, you see the following error message:

DATE your-hostname sshd: /etc/ssh/sshd_config: terminating, # bad configuration options

Description 

The # should be a number and tells you how many lines you need to correct.  For one example, the user accidentally hit "i" in vi too many times, resulting in a line starting with "i".  In another example, the user accidentally put a space between Password and Authentication in the PasswordAuthentication option.  Both of those resulted in unknown (bad) configuration options, preventing SSHD from starting.

Workaround

Edit the /etc/ssh/sshd_config file to correct the configuration options.