In general, you only need to worry about the "Warning" message if it is causing you issues.
As to how to fix It would depend greatly on what the Crestron system is doing - is it processing all the audio, if so, can the audio path through the Crestron be altered to reduce the processing and delay on the audio? Is the Crestron handling the echo control? If so, you may be able to turn the echo control off on the codec. It's very hard to say without knowing what the equipment you have connected to the codec is, or what it is programmed to do. Perhaps a better approach would be to speak with your AV Integrator who set up and supports your Crestron equipment to see what they can do to assist as they would know in more detail how their setup works.
Wayne
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