WHMCS v7 and v8
Potential Character Encoding Issue
Historically WHMCS used a mix of database character sets and collations. If you have a particularly old WHMCS installation this may cause character encoding issues when certain special characters are displayed in SupportPal.
Two solutions are available to resolve the issue:
Fix the WHMCS database
WHMCS provides guidance in their documentation: https://docs.whmcs.com/Database_Collations#Editing_Database_Collations. We would recommend to contact them for further assistance.
Fix after the migration
This approach should be a last resort as it requires fixing bad data as you come across it. It also requires good understanding of MySQL queries.
columnwith name of the table and column which contains bad data:
UPDATE `table` SET `column`=convert(cast(convert(`column` using latin1) as binary) using utf8)