Error when trying to unmarshal json to frame using frame.UnmarshalJSON()

Hi when i’m trying to unmarshal a json to a frame and then send it to the actual panel, it founds an unexpected field that is the first key in the json message, is this a common problem? or i’m doing something wrong?

errorUnmash := frame.UnmarshalJSON(<-moduleMessage)
if errorUnmash != nil {
	log.DefaultLogger.Error("Error frame generation", "errorUnmash",errorUnmash)
}

=2022-04-15T11:09:26+0000 lvl=eror msg="Error frame generation" logger=plugins.backend pluginId=streaming-datasource-plugin errorUnmash="bind l1: unexpected field: _Class, error found in #10 byte of ...|{\"_Class\": \"Overhead|..., bigger context ...|{\"_Class\": \"Overhead_crane_status\", \"Yard_ID\": \"MA\", \"Line_I|..."

My guess would be that the JSON has an invalid format. Are you able to share an (anonymous) example of what you’re passing to the UnmarshalJSON method?