The following error is logged in the VNM.OUT file:
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[libprotobuf ERROR ..\..\..\..\third_party\protobuf\src\google\protobuf\wire_format_lite.cc:629] String field 'SpectrumCMGRPC.ConfigText.configText' contains invalid UTF-8 data when serializing a protocol buffer. Use the 'bytes' type if you intend to send raw bytes.
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The following error is also seen in the NCMSERV.OUT file
SEVERE: Exception while executing runnable io.grpc.internal.ServerImpl$JumpToApplicationThreadServerStreamListener$1@6b93a571
io.grpc.StatusRuntimeException: INTERNAL: Invalid protobuf byte sequence
Release : 10.4.3, 21.2.8
Component : SPCAPP - NCM
Protobuf errors are displayed on VNM.OUT when non-utf-8 characters sent to ncmservice on the configText.
For Spectrum 21.2.8 please open up a support issue and request patch 21.02.08.D66
This problem is also solved natively in Spectrum 22.2.1 release :