Hi, my portfolio single page items all of a sudden only show "Error 404 - Page not found". no new plugins were installed and I reset the permalinks to be sure. Please can you have a look:
please go to Settings > Permalinks section and click "Save changes" button. If this won't help, then switch to default permalinks and save it again. 404 are always related with permalinks and .htaccess files.
So if you still have the same issue, you should contact with server admin because something wrong happened with .htaccess file on server side as this error is due to server always. Before that, you can also deactivate all plugins but we are not sure if this will help.
Comments
please go to Settings > Permalinks section and click "Save changes" button. If this won't help, then switch to default permalinks and save it again. 404 are always related with permalinks and .htaccess files.