Two-Factor Authentication fails to enable with failed to load and to parse the file tfa_userdata.json

Symptoms

When enabling Two-Factor Authentication in the WHM interface, you are presented with a failure to load and parse errors relating to the tfa_userda.json file.

Description 

Failed to fetch user configurations: (XID kyf29j) The system failed to load and to 
parse the file “/var/cpanel/authn/twofactor_auth/tfa_userdata.json” because of an 
error: (XID uzway2) The system failed to parse the JSON stream data “‘{}’ ” for 
the caller “(eval)” because of an error: malformed JSON string, neither tag, array, 
object, number, string or atom, at character offset 0 (before "\x{e2}\x{80}\x{98}{}...") 
at /usr/local/cpanel/Cpanel/JSON.pm line 123.

Workaround

Verify your JSON file is valid. This can be done with the json_pp library if it is loaded or through python directly. 

json_pp < /var/cpanel/authn/twofactor_auth/tfa_userdata.json

python -m json.tool /var/cpanel/authn/twofactor_auth/tfa_userdata.json

If you get an error, verify the contents of the file are only "{}"