With this module you can easily disable languages from the WHMCS client area.
Copy the disable_languages folder in modules/addons/ to your WHMCS installation.
- In the WHMCS admin area navigate to Setup->Addon Modules.
- Find the module Disable Languages and activate it.
- Don't forget to configure the permissions!
- Navigate to Addons->Disable Languages.
- select the language you want to be available from de client area.
- Hit the save button.
- Check your client area