This could be bad data in the file. Have the user open their call list up in excel and have them do a A-Z sort and a Z-A sort looking for any funky characters or numbers that would be invalid. Have them remove all characters except for numbers in the phone number field and re-scrub. If this doesn’t work, have them save it as a different file format (usually they have excel so save it as .csv) and it may fix the problem. If not, the list may need to be inspected by us.