Safe restores require matching the backup environment as closely as possible.
Restoring files without the database, or vice versa, often causes mismatches.

Always restore the database first, then files, then update wp-config.php. Afterward, regenerate permalinks and clear caches.

Check for version mismatches, especially PHP and MySQL versions, which can cause silent failures.

The most common mistake is restoring backups directly onto live sites without testing.
The takeaway is to treat restores like migrations, not simple file uploads.