Use correct method to write error message in JSP

experiment/src/org/labkey/experiment/ExperimentRunGraph.java

@@ -49,11 +49,23 @@ public static void renderSvg(Writer out, Container c, ExpRunImpl run, boolean de
     private static String getSvg(String dot) throws ExecuteException
     {
         Graphviz graph = DotParser.parse(dot);
-        String svg = graph.toSvgStr();
 
-        // Scale down to 50% of default size. This is arbitrary but seems reasonable. Diagrams are larger than
-        // the old image-based ones, but monitors are much higher resolution than when those were scaled.
-        return SvgUtil.scaleSize(svg, 0.5f);
+        if (graph.isEmpty())
+            return ""; // Graphviz.toSvgStr() throws an exception if the graph is empty.
+
+        try
+        {
+            String svg = graph.toSvgStr();
+
+            // Scale down to 50% of default size. This is arbitrary but seems reasonable. Diagrams are larger than
+            // the old image-based ones, but monitors are much higher resolution than when those were scaled.
+            return SvgUtil.scaleSize(svg, 0.5f);
+        }
+        catch (ExecuteException ex)
+        {
+            LOG.warn("Error generating graph", ex);
+            throw ex;
+        }
     }
 
     private static String getDotGraph(Container c, ExpRunImpl run, boolean detail, String focus, String focusType)

experiment/src/org/labkey/experiment/controllers/exp/experimentRunGraphView.jsp

@@ -69,7 +69,7 @@
     }
     catch (ExecuteException e)
     {
-        out.print("<p>Error rendering graph</p>");
+        out.write("<p class=\"labkey-error\">Error rendering graph</p>");
     }
 
     if (isSummaryView)