SQL Server 2016 Database Backup and Restore
Note: to get the best help on this question, please include your actual RESTORE statement, and the specific error message that you're getting.

When using In-Memory OLTP, SQL Server has to create a new folder named "xtp" in the root of the default file location for the SQL Server instance.  This folder contains the DLLs for compiled stored procedures and other in-memory objects.  You can find more details about that here: 

In-Memory OLTP files –what are they and how can I relocate them?

If you've changed the location for your data files, you may need to update SQL Server's access to the file system there:

Configure File System Permissions for Database Engine Access

As a test / workaround, you could manually create the "xtp" folder, and then try the restore again.