The CX3000 is a LYNC only phone and to my knowledge would not output an Error Message like the above.
The type of error you posted points to one of our SoundStation / SoundStation / VVX Phones.
This usually happens when the phone receives and RTP packet before the phone has setup an RTP connection.
I would suggest you try and reproduce this issue and provide your Polycom reseller with a wireshark trace so they can raise a case with Polycom support if needed.
Please ensure to provide some feedback if this reply has helped you so other users can profit from your experience.
Polycom Global Services
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