diff --git a/code-push-plugin-testing-framework/script/platform.js b/code-push-plugin-testing-framework/script/platform.js
index 64bc3003..4a4ff4b8 100644
--- a/code-push-plugin-testing-framework/script/platform.js
+++ b/code-push-plugin-testing-framework/script/platform.js
@@ -406,8 +406,13 @@ var IOSEmulatorManager = (function () {
     /**
      * Ends a running application given its app id.
      */
-    IOSEmulatorManager.prototype.endRunningApplication = function (appId) {
-        return testUtil_1.TestUtil.getProcessOutput("xcrun simctl terminate booted " + appId, undefined).then(function () { return null; })
+    IOSEmulatorManager.prototype.endRunningApplication = async function (appId) {
+        const isAppRunning = await isAppRunningOnIOS(appId);
+        if (!isAppRunning) {
+            return null;
+        }
+        await testUtil_1.TestUtil.getProcessOutput("xcrun simctl terminate booted " + appId, undefined);
+        return null;
     };
     /**
      * Restarts an already installed application by app id.
@@ -466,6 +471,18 @@ var IOSEmulatorManager = (function () {
 }());
 exports.IOSEmulatorManager = IOSEmulatorManager;
 
+/**
+ * Returns whether the app is currently running on the booted simulator.
+ *
+ * "xcrun simctl terminate" fails when the app is not running, and it reports that the same way it reports
+ * a genuinely broken simulator, so the running state has to be established up front instead. Running apps
+ * appear in launchctl's job list as "UIKitApplication:<bundle id>[...]" with a live pid.
+ */
+async function isAppRunningOnIOS(appId) {
+    const output = await testUtil_1.TestUtil.getProcessOutput("xcrun simctl spawn booted launchctl list", { noLogCommand: true, noLogStdOut: true, noLogStdErr: true });
+    return output.includes(appId);
+}
+
 function commandWithCheckAppExistence(command, appId) {
     return testUtil_1.TestUtil.getProcessOutput("adb shell pm list packages", { noLogCommand: true, noLogStdOut: true, noLogStdErr: true })
         .then((output) => {
diff --git a/code-push-plugin-testing-framework/script/testBuilder.js b/code-push-plugin-testing-framework/script/testBuilder.js
index 8b324eb5..286be44f 100644
--- a/code-push-plugin-testing-framework/script/testBuilder.js
+++ b/code-push-plugin-testing-framework/script/testBuilder.js
@@ -34,7 +34,11 @@ function describeInternal(func, description, spec, scenarioPath) {
             ServerUtil.testMessageResponse = undefined;
         });
         beforeEach(function () {
-            return TestContext.targetPlatform.getEmulatorManager().prepareEmulatorForTest(TestConfig.TestNamespace);
+            return TestContext.targetPlatform.getEmulatorManager().prepareEmulatorForTest(TestConfig.TestNamespace)
+                .catch(function (error) {
+                    console.error("Failed to prepare emulator/simulator for the test.");
+                    throw error;
+                });
         });
         if (scenarioPath) {
             before(function () {