If you are trying to migrate the entire site, make sure when migrating the site, you have selected everything(database + files).
If you are sure that you have included everything when performing the migration, then you can check the following possible causes and solutions to this issue:
1. Restore was not completed successfully
Please make sure that the restore was completed successfully. Did you see the success message after the restoration? If you did not see the message, please run the restoration again and wait for the success message to pop up, then check the website again.
2.This can be a database service problem
In this case, please go to WPvivid settings > Advanced settings > Choose PDO in Database Access Method > Save Changes, then try to perform the migration again.
3. Cache, firewall, 301 redirect plugins
Please temporarily deactivate cache plugins and firewall plugins on the source site, then run migration again.