When enabling an application metering policy to 'deny from running' the user receives a popup box that says 'This program is blocked by group policy.' This message appears in addition to the application metering denial message and even occurs when the 'Inform user' check box is disabled.
This is a known limitation.
When the Application Metering driver prevents a process from launching, the application from where that process was launched (typically Windows Explorer or NC-like file manager) may show it’s own error message even if "Inform user" checkbox is disabled in the policy.
Unfortunately as it is a known limitation there is nothing more we an do at this time.