Reproduced problem in a test.

core/src/main/java/jenkins/model/DownloadSettings.java

@@ -49,7 +49,7 @@ import org.kohsuke.stapler.StaplerRequest;
         return Jenkins.getInstance().getInjector().getInstance(DownloadSettings.class);
     }
 
-    private boolean useBrowser = true; // historical default, not necessarily recommended
+    private boolean useBrowser = false; // TODO switch saved preferences one time, or add an admin monitor, or just delete the option (in which case can also delete DownloadServiceTest and its testPost.jelly)
     
     public DownloadSettings() {
         load();

test/src/test/java/hudson/model/DownloadService2Test.java

+/*
+ * The MIT License
+ *
+ * Copyright 2015 Jesse Glick.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package hudson.model;
+
+import hudson.util.FormValidation;
+import org.junit.Test;
+import static org.junit.Assert.*;
+import org.junit.Rule;
+import org.jvnet.hudson.test.JenkinsRule;
+
+public class DownloadService2Test {
+
+    @Rule public JenkinsRule r = new JenkinsRule();
+
+    //@Issue("SECURITY-163")
+    @Test public void updateNow() throws Exception {
+        for (DownloadService.Downloadable d : DownloadService.Downloadable.all()) {
+            FormValidation v = d.updateNow();
+            assertEquals(v.toString(), FormValidation.Kind.OK, v.kind);
+        }
+    }
+
+}