I really have no idea, but checking the code base, that error is thrown when a field type supports options (like a dropdown or checkbox set) and the data posted at save is unpopulated or is not an array. If you’re familiar with the developer tools in Firefox or Chrome, visit that page and submit the form, then see what the $_POST payload looks like.
Code reference: https://buddypress.trac.wordpress.org/browser/trunk/src/bp-xprofile/classes/class-bp-xprofile-field.php#L1074
I can’t see what moving hosts would change here, but the internet is a fragile thing. 🙂
