transferring site to new host and new domain

There are URLs and paths stored in the database in ‘serialized’ form where the string length is stored along with the string. You must use special tools to search and replace the old values with the new ones.

If you replace an old URL with a new one of a differnt length, it will break the serialization, causing many different problems.

If the old site is still available, you can use the steps shown in this article to copy the site: https://wordpress.mcdspot.com/2012/08/22/migrating-a-wordpress-site-step-by-step/

If the old site is not available, and you still have a copy of the database from that site, you should be able to use this tool to make the changes: https://interconnectit.com/products/search-and-replace-for-wordpress-databases/