diff --git a/metrics.go b/metrics.go
index e153430..1bc4c2d 100644
--- a/metrics.go
+++ b/metrics.go
@@ -38,7 +38,7 @@ func metricsHandler(response http.ResponseWriter, request *http.Request) {
 		property, ok := request.URL.Query()["property"]
 		if !ok || len(property[0]) < 1 {
 			log.Println("Url Param 'property' is missing")
-			fmt.Fprintf(response, "{ \"msg\": \"property must be specified in URL\" }")
+			fmt.Fprintf(response, "{ \"msg\": \"error: property must be specified in URL\" }")
 			return
 		}
 
@@ -46,7 +46,7 @@ func metricsHandler(response http.ResponseWriter, request *http.Request) {
 
 		if !ok || len(deveui[0]) < 1 {
 			log.Println("Url Param 'deveui' is missing")
-			fmt.Fprintf(response, "{ \"msg\": \"deveui must be specified in URL\" }")
+			fmt.Fprintf(response, "{ \"msg\": \"error: deveui must be specified in URL\" }")
 			return
 		}
 		// Query()["deveui"] will return an array of items,
@@ -55,7 +55,7 @@ func metricsHandler(response http.ResponseWriter, request *http.Request) {
 
 		if !(Contains(getMyDevs(name), mydeveui)) {
 			log.Println("specified 'deveui' does not belong to this user")
-			fmt.Fprintf(response, "{ \"msg\": \"specified deveui does not belong to this user\" }")
+			fmt.Fprintf(response, "{ \"msg\": \"error: specified deveui does not belong to this user\" }")
 			return
 		}
 
@@ -334,7 +334,7 @@ func getLastMetrics(deveui string) OneMetric {
 				res.Weight = value
 				i, err := strconv.Atoi(value)
 				if err == nil {
-					res.Weight_kg = fmt.Sprintf("%.2f", float64(i)/1000.0)
+					res.Weight_kg = fmt.Sprintf("%.3f", float64(i)/1000.0)
 				} else {
 					res.Weight_kg = "ERR"
 				}
diff --git a/snippets/graph.html b/snippets/graph.html
index 2b5f2e0..d7c4c82 100644
--- a/snippets/graph.html
+++ b/snippets/graph.html
@@ -184,7 +184,7 @@ function drawGraph(deveui, alias, property, start, stop, create_graph) {
     maxfunc = function(max) { return max + 2000 }
     labels = {
       formatter: function(val, index) {
-        return (val / 1000.0).toFixed(2);
+        return (val / 1000.0).toFixed(3);
       }
     };
   } else if (property==="h") {
@@ -212,6 +212,12 @@ function drawGraph(deveui, alias, property, start, stop, create_graph) {
   <div class="message-body">
     Abo ist abgelaufen
   </div>
+</article>`);
+      } else if (mydata.msg.includes("error:")) {
+        $('#chart').html(`<article class="message is-danger">
+  <div class="message-body">
+    Fehler im Aufruf
+  </div>
 </article>`);
       } else {
         location.reload(true);