elisewarfield on "Cookie Error Preventing Login"

I'm unable to login to the admin panel of my wordpress site. When I type the url of my login page, I receive the message

ERROR: Cookies are blocked due to unexpected output. For help, please see this documentation or try the support forums.

When I enter the useame & password, it kicks me back to the login page with the same error. (Support forums about a similar issue on version 3.X suggested repeatedly entering useame & password. This did not work.)

I've enabled all cookies, including 3rd party cookies on my browsers. I've also tried clearing all cookies, restarting the browser and attempting to login again. This issue is across all browsers (Chrome, safari, firefox and vivaldi).

I was able to login after my most recent edits in the admin panel. Regardless, I have attempted to upload a previous version of the site (prior to the last changes) and this did not fix the problem.

Does anyone have a fix for this?