WordPress Error occurred: 404 – not found

Solution:1

Links of your site pages and post are not correctly modified to new server. you need to get .xml file from old server then change links manually using notepad or some other editor, then import that file with changes links to new server. Also you need to set permalinks for site as it was for old site.

Solution:2

Login to dashboard and change the permalink of your site to default. And recheck your site. If it works it will be great and if it doesn’t work check your database by downloading it.