If the PHP version of your website PHP is different to the PHP version of your backup it might cause problems with proper functioning of your website and may cause issues with some applications. This is happens more commonly with migrations from PHP 5 to PHP 7.
We recommend that users back up their WordPress sites or network of sites regularly. You can also set up automatic backups using All-in-One WP Migration plugin extensions. Always make sure your plugin version is up to date.
In most cases, WordPress and popular plugins will not be affected by PHP update. However, there is a possibility that some plugins or other functionalities stop working.
These are some steps that you can take if you have issues on a migration with different PHP versions.
1. Make sure that all plugins are deactivated. This will ensure your website error is not caused by any third-party software
2. Switch to your default WordPress theme and Deactivate all other themes. This action will make sure that the error is not due to code in your themes
3. Set WP_DEBUG constant to true in wp-config.php file in your WordPress installation path so that you can see all errors, warnings and notes that are received from the website during execution. This will help you to locate any problems
4. Check the error.log file in the All-in-One WP Migration plugin Storage folder. The error.log file will show you all errors and error message content received during execution. This is another approach to locating any issues and will help you narrow the problem area
5. Downgrade your PHP version to 5. This change can be applied from your hosting control panel. Some web hosts may allow you to change your PHP version.
If none of the above helps, you might need to change your WordPress hosting.