Error in WordPress import

Error in WordPress import

I am changing my website hosting, so I made a backup for everything,
themes, DB and used the Export utility in WP to export all posts,
pages...etc.
Now I am trying to import posts, pages, users in the new hosting but I am
getting the following errors:
Failed to create new user for John Their posts will be attributed to the
current user. Failed to create new user for guest. Their posts will be
attributed to the current user. Failed to create new user for Sam. Their
posts will be attributed to the current user. Failed to import Media "MW
profile" Failed to import Media "LA house" Failed to import Media "Gold"
Failed to import Media "Archive" Failed to import Media "21882183"
....etc
I checked the import xml file, paths inside it but I don't see any problem
as paths in the import XML file are exactly the same as images real paths.
So can someone please tell me what I might be doing wrong here, and how to
solve this problem?
thanksf or your time