Port in request contains numbers for multiple countries or that are not in E.164 format.
There are phone numbers in the port in request from multiple countries.
There are phone numbers in the port in request that are not in E.164 format and so the country cannot be identified.
Please review the list of phone numbers and submit one port in request for all numbers from each country. A port in request can only contain phone numbers from one country.
Also double check that all phone numbers are in E.164 format so that Twilio can correct identify the country code. https://www.twilio.com/docs/glossary/what-e164