Error 404 :-(

My webpage is https://www.picincinnati.com
When I view it from my phone or computer I have no issues but I have had clients tell me that when they click on galleries to view them, they receive an error 404 message. The first time was “error 404 page post or resource cannot be found”. I thought changing my permalink structure back to the default would solve the issue. I had the client check again and this time it said “error 404 not found and no server”

HELP