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
---------------- The title Polycom Employee & Community Manager is a community setting and does not reflect my role. I am just a simple volunteer in the community like everybody else. My official "day" Job is 3rd Level support at Poly but I am unable to provide official support via the community.
Notice: This community forum is not an official Poly support resource, thus responses from Poly employees, partners, and customers alike are best-effort in attempts to share learned knowledge. If you need immediate and/or official assistance please open a service ticket through your proper support channels. Please also ensure you always check the VoIP , Video Endpoint , Skype for Business , PSTN or RPM FAQ's