NewExceptionTelemetry generates Problem Id: string

[saraseward]

client := appinsights.NewTelemetryClient(instrumentationKey)
trace3 := appinsights.NewExceptionTelemetry("esempiooooo")
w.client.Track(trace3)

This generates an error on Azure:

I also tried with:

	trace3 := appinsights.NewExceptionTelemetry("esempio1")
	w.client.Track(trace3)
	w.client.TrackException(trace3)
	trace6 := appinsights.NewExceptionTelemetry(errors.New("esempio2"))
	w.client.Track(trace6)
	w.client.TrackException(trace6)
	w.client.TrackException("esempio3")

What am I doing wrong?