Doubles in Message cause truncation

[Randy Nuss]

I'm having an issue where fields in my .proto file with type 'double' do not get serialized and seem to cause the serialization process to halt and truncate the remaining message.  If I change from 'double' to 'float' then SerializeToString() and ParseFromString() work as expected.

Coding:   C++

Compiler:   Visual Studio 2019

Architecture selection:   amd64

Protobuf Library and protoc:   protobuf_x64-windows-static

syntax = "proto3";

package decodedBuff;

message Parameter {

    string metric_units = 1;

    string units = 2;

    double test1 = 3;

    double value = 4;

    int32 decode_type = 5;

    string source = 6;

}

// Serialize the message
static std::string buff;
parmList.SerializeToString(&buff);