Pages do not load after migration to new server

We cannot investigate the server-side problem this way since we don’t have access to it and probably the moderator will mark it off-topic.

However, these are common troubleshooting points that you can try to fix this kind of issue: –

  • Try saving the permalinks for once and refresh. Go to Admin Dashboard > Settings > Permalinks > Save Permalinks
  • Check what is exactly the critical error. Go to wp-config.php and add define( 'WP_DEBUG', true); define( 'WP_DEBUG_DISPLAY', true); This will start displaying the actual error instead of just saying critical error.
  • Do you see other posts or content in the backend? Since you said Hello World is loading fine but not others. This seems like old site database is not imported correctly. Import the DB again.
  • Hire an expert to investigate and fix the issue via Upwork (mine) etc.