In order to correct this issue, please follow these steps:
1. Go into your WHMCS file structure and open the configuration.php file, located in the root of your WHMCS installation.
2. Check to see if the following line exists:
If it does, please confirm that the value entered is the correct charset for your database's collation. You can see a reference chart for charset values here.
If the value does not exist, please add it at the bottom of the file and ensure that the charset entered is the correct charset for your database's collation.
3. Login to your MySQL database and confirm that the collation setting for the following tables, and table columns, match (depending on module):
WordPress Auto-Provision Module
WHMCS Auto-Provision Module
Product Image Module
Note: Be sure to check that both the table and table columns all have a matching collation value. We recommend modifying our "mod_" table to match your WHMCS installation, before attempting to modify the WHMCS tables.
4. Log back into WHMCS and go to (Setup -> Addon Modules ). Deactivate and reactivate the effected module and check to see if the issue is resolved.
If you are still unable to resolve with the above steps, please submit a support ticket and include your WHMCS and WHM login details, so that we can address the issue further.