Export of posts is a different size each time and error received when importing.

I’m currently trying to migrate a website from one host to GoDaddy. Whenever I export my posts from the original WordPress installation I get a xml file of a different size (between 80 and 90mb), and then when I try to import it to the new host the upload errors out and, I get the following error:

Sorry, there has been an error.
File is empty. Please upload something more substantial. This error could also be caused by uploads being disabled in your php.ini or by post_max_size being defined as smaller than upload_max_filesize in php.ini.

My php.ini and info.php files are set to let me upload up to 192mb, so I’m not sure what the issue could be.