404 Error On All Gallery Links On Front End

Hi,  Backend is working OK,   when I go to view on website ,  all galleries return a 404 error.   

UPDATE. "View on website" brings me back to wordpress site,  not folder site.

UPDATE:  this link with bring me to the home page. "https://fran.ie/gallery/index.php"   but when I search for a gallery with password 212121. I am brought back to wordpress

Where do you think I sould focus my trouble shooting,  thanks

Sytist is located in a folder not sub domain

https://fran.ie/gallery/weddings-and-events/21stdo...

The file/folder for that page is missing, moved or deleted from the server. So you will have to recreate that gallery from scratch.

Thanks Tim,   Two folders were not transferred,  I uploaded them to the right location and all OK,    Thanks for your help.