Permalinks Page 404

I have a site that has been live and working great for a while. I randomly went to look at a settings page and realized recently that the permalinks page in the backend is not working. Any time I click on it I get a 404. But all other pages on the front end and the back end work fine from what I can tell. I have tried turning off all plugins and changing over to the default theme but none of that seems to make a difference.

All plugins and wordpress core files as well as the theme have been updated to the most current versions during the process of troubleshooting thinking it was possible that it was an update issue.

I am have a separate issue but I believe that one is more template related but the lightbox all of the sudden stopped working today as I was adding photos to the site. and troubleshooting the permalinks issue but I have put everything back and it does not seem to fix it. any time I click on a photo on the front end it loads to the image directly instead of the lightbox in front o the page.

Thank you in advanced for any possibly solutions.