If the website has been not maintained properly then experiencing WordPress error 404is quite common among the users. It mainly occurs when you click on a link of any missing page of the site. When clicking on the link, the WordPress server will send the user an error message to you. Any issue with permalinks will make this error to happen. So for this, just log in to your WordPress and then go to the dashboard. Now, find the setting option and then choose the Permalinks. Make sure to choose the Default settings and then save the changes.
If after changing the permalinks youre again facing the same problem then it is the time to access the .htaccess file. For this, the user is needed to set all files as visible in your FTP. After this, check if your browser is working fine.