Even though marshalling appears to work properly, the following warning messages can be seen when using the marshaler to Unmarshal messages:

proto: no encoder for wall uint64 [GetProperties]
proto: no encoder for ext int64 [GetProperties]
proto: no encoder for loc *time.Location [GetProperties]

We should figure out why this is happening and fix the warnings. It may have something to do with the user of encoding/json in Unmarshalling.