Since the last CiviCRm version 4.7.21 to 4.7.23, I have the display_name empty. There is also the trouble for the sort_name.
I found the report of SarahG (FountainTribe) here https://forum.civicrm.org/index.php?topic=33928.msg143820#msg143820 It states that :
The return value from "CRM_Utils_Address::format" is returning an empty string for the display name and the sort name. Those empty strings cause the calling function to use email address instead.
I applied her solution :
In the file /CRM/Contact/BAO/Individual.php (around 210 -215) I replaced the line: Code: $displayName = CRM_Utils_Address::format($formatted, $format, FALSE, FALSE, TRUE, $tokenFields );
New line: Code: $displayName = $firstName." ".$lastName;
Did similar replacement for the $sortName variable.
This solved the trouble. But as she stated, it is only a temporary solution.
Does anyone still encountered this issue with CiviCRm version 4.7.23 ?