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.