[SOLVED] Problem importing settings from 3.4.9 into 3.7.15

1. I exported a site to XML and successfully imported it elsewhere.
2. The first site uses Ata 3.4.9. The second site uses Ata 3.7.15.
3. The contents of the settings file exported from the first site when pasted into the second, causes the message that it doesn't appear to be a valid settings file.

Can you please point me to a solution for this? I should add that I only have access to the browser/dashboard in Wordpress so can't do anything particularly technical. I'm not particularly technically adept, either, so please bear that in mind