404 Error page for Galleries

Hello, I use this plugin for my photography portfolio and it has been working beautifully at the beginning. However, now I’m experiencing an error page when trying to access individual galleries. The categories pages work properly but /portfolio/gallery-name cannot be found and gives me a Cannot be found page. Is there something I might have messed up? I tried to re-activate the plugin which fixes the issue for a small amount of time. Thank you!