Message not displaying properly

Hi,

I am displaying a message from a custom message class with placeholder as follows:

Message i012(zmsg_class) with text-001 text-002 text-003 text-004.

In development client it is displayed properly, but in the quality client it is displayed as follows:

I:ZMSG_CLASS:012 <Msg content from text elements>

What could be the reason for the message to be prefixed with I:ZMSG_CLASS:012.

Thanks and Regards,

Taiyeb