diff --git a/README.md b/README.md
index 23ad402..db93bf4 100644
--- a/README.md
+++ b/README.md
@@ -32,20 +32,42 @@ The following table compares the steps needed to run the solution on the IoT Edg
 
 ## Quickstart
 1. Setup
+
+    Windows
     ```
-    iotedgehubdev setup -c <edge-device-connection-string>
+    iotedgehubdev setup -c "<edge-device-connection-string>"
+    ```
+
+    Linux/macOS
+    ```
+    sudo iotedgehubdev setup -c "<edge-device-connection-string>"
     ```
 
 2. Start/stop an IoT Edge solution in simulator
+
+    Windows
     ```
-    iotedgehubdev start -d <path/to/deployment manifest>
+    iotedgehubdev start -d <path/to/deployment-manifest>
     iotedgehubdev stop
     ```
 
+    Linux/macOS
+    ```
+    sudo iotedgehubdev start -d <path/to/deployment-manifest>
+    sudo iotedgehubdev stop
+    ```
+
 3. Start and debug a single module natively
     1. Start the module with specific input(s)
+
+        Windows
         ```
-        iotedgehubdev start -i <module-inputs>
+        iotedgehubdev start -i "<module-inputs>"
+        ```
+
+        Linux/macOS
+        ```
+        sudo iotedgehubdev start -i "<module-inputs>"
         ```
 
         For example: `iotedgehubdev start -i "input1,input2"`
@@ -61,6 +83,17 @@ The following table compares the steps needed to run the solution on the IoT Edg
 
         For example:
         `curl --header "Content-Type: application/json" --request POST --data '{"inputName": "input1","data": "hello world"}' http://localhost:53000/api/v1/messages`
+    5. Stop the simulator
+
+        Windows
+        ```
+        iotedgehubdev stop
+        ```
+
+        Linux/macOS
+        ```
+        sudo iotedgehubdev stop
+        ```
  
 ## Other resources
 - [Azure IoT Edge for Visual Studio Code](https://github.com/microsoft/vscode-azure-iot-edge)
diff --git a/iotedgehubdev/cli.py b/iotedgehubdev/cli.py
index e6a4b7c..843cf8a 100644
--- a/iotedgehubdev/cli.py
+++ b/iotedgehubdev/cli.py
@@ -49,7 +49,7 @@ def _with_telemetry(func):
             telemetry.flush()
             return value
         except Exception as e:
-            output.error('Error: {0}'.format(str(e)))
+            output.error(str(e))
             telemetry.fail(str(e), 'Command failed')
             telemetry.flush()
             sys.exit(1)
@@ -57,6 +57,29 @@ def _with_telemetry(func):
     return _wrapper
 
 
+def _parse_config_json():
+    config_file = HostPlatform.get_config_file_path()
+
+    if not Utils.check_if_file_exists(config_file):
+        raise ValueError('Cannot find config file. Please run `{0}` first.'.format(_get_setup_command()))
+
+    with open(config_file) as f:
+        try:
+            config_json = json.load(f)
+
+            connection_str = config_json[CONN_STR]
+            cert_path = config_json[CERT_PATH]
+            gatewayhost = config_json[GATEWAY_HOST]
+
+            return EdgeManager(connection_str, gatewayhost, cert_path)
+        except (ValueError, KeyError):
+            raise ValueError('Invalid config file. Please run `{0}` again.'.format(_get_setup_command()))
+
+
+def _get_setup_command():
+    return '{0}iotedgehubdev setup -c "<edge-device-connection-string>"'.format('' if os.name == 'nt' else 'sudo ')
+
+
 @click.group(context_settings=CONTEXT_SETTINGS, invoke_without_command=True)
 @click.version_option()
 def main():
@@ -136,27 +159,13 @@ def setup(connection_string, gateway_host):
               help='Specify the output file to save the connection string. If the file exists, the content will be overwritten.')
 @_with_telemetry
 def modulecred(modules, local, output_file):
-    configFile = HostPlatform.get_config_file_path()
-    if Utils.check_if_file_exists(configFile) is not True:
-        output.error('Cannot find config file. Please run `iotedgehubdev setup` first.')
-        sys.exit(1)
-    try:
-        with open(configFile) as f:
-            jsonObj = json.load(f)
-        if CONN_STR in jsonObj and CERT_PATH in jsonObj and GATEWAY_HOST in jsonObj:
-            connection_str = jsonObj[CONN_STR]
-            cert_path = jsonObj[CERT_PATH]
-            gatewayhost = jsonObj[GATEWAY_HOST]
-            edgeManager = EdgeManager(connection_str, gatewayhost, cert_path)
-            modules = [module.strip() for module in modules.strip().split('|')]
-            credential = edgeManager.outputModuleCred(modules, local, output_file)
-            output.info(credential[0])
-            output.info(credential[1])
-        else:
-            output.error('Missing keys in config file. Please run `iotedgehubdev setup` again.')
-            sys.exit(1)
-    except Exception as e:
-        raise e
+    edge_manager = _parse_config_json()
+
+    if edge_manager:
+        modules = [module.strip() for module in modules.strip().split('|')]
+        credential = edge_manager.outputModuleCred(modules, local, output_file)
+        output.info(credential[0])
+        output.info(credential[1])
 
 
 @click.command(context_settings=CONTEXT_SETTINGS,
@@ -189,28 +198,16 @@ def modulecred(modules, local, output_file):
               help='Docker daemon socket to connect to')
 @_with_telemetry
 def start(inputs, port, deployment, verbose, host):
-    configFile = HostPlatform.get_config_file_path()
-    try:
-        with open(configFile) as f:
-            jsonObj = json.load(f)
-            if CONN_STR in jsonObj and CERT_PATH in jsonObj and GATEWAY_HOST in jsonObj:
-                connection_str = jsonObj[CONN_STR]
-                cert_path = jsonObj[CERT_PATH]
-                gatewayhost = jsonObj[GATEWAY_HOST]
-                edgeManager = EdgeManager(connection_str, gatewayhost, cert_path)
-                if host is not None:
-                    os.environ[DOCKER_HOST] = host
-            else:
-                output.error('Missing keys in config file. Please run `iotedgehubdev setup` again.')
-                sys.exit(1)
-    except Exception as e:
-        raise e
+    edge_manager = _parse_config_json()
 
-    hostname_hash, suffix = Utils.hash_connection_str_hostname(connection_str)
-    telemetry.add_extra_props({'iothubhostname': hostname_hash, 'iothubhostnamesuffix': suffix})
+    if edge_manager:
+        if host is not None:
+            os.environ[DOCKER_HOST] = host
 
-    if inputs is None and deployment is not None:
-        try:
+        hostname_hash, suffix = Utils.hash_connection_str_hostname(edge_manager.hostname)
+        telemetry.add_extra_props({'iothubhostname': hostname_hash, 'iothubhostnamesuffix': suffix})
+
+        if inputs is None and deployment is not None:
             with open(deployment) as json_file:
                 json_data = json.load(json_file)
                 if 'modulesContent' in json_data:
@@ -222,33 +219,31 @@ def start(inputs, port, deployment, verbose, host):
             except RegistriesLoginError as e:
                 output.warning(e.message())
                 telemetry.add_extra_props({'failloginregistries': len(e.registries())})
-            edgeManager.start_solution(module_content, verbose)
+            edge_manager.start_solution(module_content, verbose)
             if not verbose:
                 output.info('IoT Edge Simulator has been started in solution mode.')
-        except Exception as e:
-            raise e
-    else:
-        if deployment is not None:
-            output.info('Deployment manifest is ignored when inputs are present.')
-        if inputs is None:
-            input_list = ['input1']
         else:
-            input_list = [input_.strip() for input_ in inputs.strip().split(',')]
+            if deployment is not None:
+                output.info('Deployment manifest is ignored when inputs are present.')
+            if inputs is None:
+                input_list = ['input1']
+            else:
+                input_list = [input_.strip() for input_ in inputs.strip().split(',')]
 
-        edgeManager.start_singlemodule(input_list, port)
+            edge_manager.start_singlemodule(input_list, port)
 
-        data = '--data \'{{"inputName": "{0}","data":"hello world"}}\''.format(input_list[0])
-        url = 'http://localhost:{0}/api/v1/messages'.format(port)
-        curl_msg = '        curl --header "Content-Type: application/json" --request POST {0} {1}'.format(data, url)
-        output.info('IoT Edge Simulator has been started in single module mode.')
-        output.info('Please run `iotedgehubdev modulecred` to get credential to connect your module.')
-        output.info('And send message through:')
-        output.line()
-        output.echo(curl_msg, 'green')
-        output.line()
-        output.info(
-            'Please refer to https://github.com/Azure/iot-edge-testing-utility/blob/master/swagger.json'
-            ' for detail schema')
+            data = '--data \'{{"inputName": "{0}","data":"hello world"}}\''.format(input_list[0])
+            url = 'http://localhost:{0}/api/v1/messages'.format(port)
+            curl_msg = '        curl --header "Content-Type: application/json" --request POST {0} {1}'.format(data, url)
+            output.info('IoT Edge Simulator has been started in single module mode.')
+            output.info('Please run `iotedgehubdev modulecred` to get credential to connect your module.')
+            output.info('And send message through:')
+            output.line()
+            output.echo(curl_msg, 'green')
+            output.line()
+            output.info(
+                'Please refer to https://github.com/Azure/iot-edge-testing-utility/blob/master/swagger.json'
+                ' for detail schema')
 
 
 @click.command(context_settings=CONTEXT_SETTINGS,
@@ -259,13 +254,10 @@ def start(inputs, port, deployment, verbose, host):
               help='Docker daemon socket to connect to')
 @_with_telemetry
 def stop(host):
-    try:
-        if host is not None:
-            os.environ[DOCKER_HOST] = host
-        EdgeManager.stop()
-        output.info('IoT Edge Simulator has been stopped successfully.')
-    except Exception as e:
-        raise e
+    if host is not None:
+        os.environ[DOCKER_HOST] = host
+    EdgeManager.stop()
+    output.info('IoT Edge Simulator has been stopped successfully.')
 
 
 main.add_command(setup)
diff --git a/iotedgehubdev/edgemanager.py b/iotedgehubdev/edgemanager.py
index cf0183f..921b52f 100644
--- a/iotedgehubdev/edgemanager.py
+++ b/iotedgehubdev/edgemanager.py
@@ -42,14 +42,18 @@ class EdgeManager(object):
 
     def __init__(self, connection_str, gatewayhost, cert_path):
         connection_str_dict = Utils.parse_device_connection_str(connection_str)
-        self.hostname = connection_str_dict[EC.HOSTNAME_KEY]
-        self.device_id = connection_str_dict[EC.DEVICE_ID_KEY]
-        self.access_key = connection_str_dict[EC.ACCESS_KEY_KEY]
-        self.compose_file = None
-        self.gatewayhost = gatewayhost
-        self.device_uri = '{0}/devices/{1}'.format(self.hostname, self.device_id)
-        self.cert_path = cert_path
-        self.edge_cert = EdgeCert(self.cert_path, self.gatewayhost)
+        self._hostname = connection_str_dict[EC.HOSTNAME_KEY]
+        self._device_id = connection_str_dict[EC.DEVICE_ID_KEY]
+        self._access_key = connection_str_dict[EC.ACCESS_KEY_KEY]
+        self._compose_file = None
+        self._gatewayhost = gatewayhost
+        self._device_uri = '{0}/devices/{1}'.format(self._hostname, self._device_id)
+        self._cert_path = cert_path
+        self._edge_cert = EdgeCert(self._cert_path, self._gatewayhost)
+
+    @property
+    def hostname(self):
+        return self._hostname
 
     @staticmethod
     def stop(edgedockerclient=None):
@@ -117,7 +121,7 @@ class EdgeManager(object):
         edgedockerclient.copy_file_to_volume(
             EdgeManager.INPUT, EdgeManager.MODULE_VOLUME, self._device_cert(),
             module_mount,
-            self.edge_cert.get_cert_file_path(EC.EDGE_DEVICE_CA))
+            self._edge_cert.get_cert_file_path(EC.EDGE_DEVICE_CA))
         edgedockerclient.start(inputContainer.get('Id'))
 
     def config_solution(self, module_content, target, mount_base):
@@ -152,7 +156,7 @@ class EdgeManager(object):
 
         network_info = {
             'NW_NAME': EdgeManager.NW_NAME,
-            'ALIASES': self.gatewayhost
+            'ALIASES': self._gatewayhost
         }
 
         compose_project = ComposeProject(module_content)
@@ -233,13 +237,13 @@ class EdgeManager(object):
 
         edgedockerclient.copy_file_to_volume(
             EdgeManager.CERT_HELPER, EdgeManager.HUB_VOLUME, EdgeManager._chain_cert(),
-            hub_mount, self.edge_cert.get_cert_file_path(EC.EDGE_CHAIN_CA))
+            hub_mount, self._edge_cert.get_cert_file_path(EC.EDGE_CHAIN_CA))
         edgedockerclient.copy_file_to_volume(
             EdgeManager.CERT_HELPER, EdgeManager.HUB_VOLUME, EdgeManager._hubserver_pfx(),
-            hub_mount, self.edge_cert.get_pfx_file_path(EC.EDGE_HUB_SERVER))
+            hub_mount, self._edge_cert.get_pfx_file_path(EC.EDGE_HUB_SERVER))
         edgedockerclient.copy_file_to_volume(
             EdgeManager.CERT_HELPER, EdgeManager.MODULE_VOLUME, self._device_cert(),
-            module_mount, self.edge_cert.get_cert_file_path(EC.EDGE_DEVICE_CA))
+            module_mount, self._edge_cert.get_cert_file_path(EC.EDGE_DEVICE_CA))
 
     def start(self, modulesDict, routes):
         return
@@ -258,7 +262,7 @@ class EdgeManager(object):
 
     def outputModuleCred(self, names, islocal, output_file):
         connstrENV = 'EdgeHubConnectionString={0}'.format('|'.join([self.getOrAddModule(name, islocal) for name in names]))
-        deviceCAEnv = 'EdgeModuleCACertificateFile={0}'.format(self.edge_cert.get_cert_file_path(EC.EDGE_DEVICE_CA))
+        deviceCAEnv = 'EdgeModuleCACertificateFile={0}'.format(self._edge_cert.get_cert_file_path(EC.EDGE_DEVICE_CA))
         cred = [connstrENV, deviceCAEnv]
 
         if output_file is not None:
@@ -272,7 +276,7 @@ class EdgeManager(object):
 
     def getModule(self, name, islocal):
         moduleUri = self._getModuleReqUri(name)
-        sas = Utils.get_iot_hub_sas_token(self.device_uri, self.access_key, None)
+        sas = Utils.get_iot_hub_sas_token(self._device_uri, self._access_key, None)
         res = requests.get(
             moduleUri,
             headers={
@@ -294,7 +298,7 @@ class EdgeManager(object):
 
     def updateModule(self, name, etag, islocal):
         moduleUri = self._getModuleReqUri(name)
-        sas = Utils.get_iot_hub_sas_token(self.device_uri, self.access_key, None)
+        sas = Utils.get_iot_hub_sas_token(self._device_uri, self._access_key, None)
         res = requests.put(
             moduleUri,
             headers={
@@ -304,7 +308,7 @@ class EdgeManager(object):
             },
             data=json.dumps({
                 'moduleId': name,
-                'deviceId': self.device_id,
+                'deviceId': self._device_id,
                 'authentication': {
                     'type': 'sas'
                 }
@@ -316,7 +320,7 @@ class EdgeManager(object):
 
     def addModule(self, name, islocal):
         moduleUri = self._getModuleReqUri(name)
-        sas = Utils.get_iot_hub_sas_token(self.device_uri, self.access_key, None)
+        sas = Utils.get_iot_hub_sas_token(self._device_uri, self._access_key, None)
         res = requests.put(
             moduleUri,
             headers={
@@ -325,7 +329,7 @@ class EdgeManager(object):
             },
             data=json.dumps({
                 'moduleId': name,
-                'deviceId': self.device_id
+                'deviceId': self._device_id
             })
         )
         if res.ok is not True:
@@ -334,7 +338,7 @@ class EdgeManager(object):
 
     def _getModuleReqUri(self, name):
         return "https://{0}/devices/{1}/modules/{2}?api-version=2018-06-30".format(
-            self.hostname, self.device_id, name)
+            self._hostname, self._device_id, name)
 
     def _generateModuleConnectionStr(self, response, islocal):
         jsonObj = response.json()
@@ -343,13 +347,13 @@ class EdgeManager(object):
         sasKey = jsonObj['authentication']['symmetricKey']['primaryKey']
         hubTemplate = 'HostName={0};DeviceId={1};ModuleId={2};SharedAccessKey={3}'
         moduleTemplate = 'HostName={0};GatewayHostName={1};DeviceId={2};ModuleId={3};SharedAccessKey={4}'
-        gatewayhost = self.gatewayhost
+        gatewayhost = self._gatewayhost
         if (islocal):
             gatewayhost = 'localhost'
         if (moduleId == '$edgeHub'):
-            return hubTemplate.format(self.hostname, deviceId, moduleId, sasKey)
+            return hubTemplate.format(self._hostname, deviceId, moduleId, sasKey)
         else:
-            return moduleTemplate.format(self.hostname, gatewayhost, deviceId, moduleId, sasKey)
+            return moduleTemplate.format(self._hostname, gatewayhost, deviceId, moduleId, sasKey)
 
     def _generateRoutesEnvFromInputs(self, inputs):
         routes = [
@@ -368,7 +372,7 @@ class EdgeManager(object):
 
     def _start_edge_hub(self, edgedockerclient, edgeHubConnStr, routes, mount_base):
         edgedockerclient.pull(EdgeManager.EDGEHUB_IMG, None, None)
-        network_config = edgedockerclient.create_config_for_network(EdgeManager.NW_NAME, aliases=[self.gatewayhost])
+        network_config = edgedockerclient.create_config_for_network(EdgeManager.NW_NAME, aliases=[self._gatewayhost])
         hub_mount = EdgeManager.HUB_MOUNT.format(mount_base)
         hub_host_config = edgedockerclient.create_host_config(
             mounts=[docker.types.Mount(hub_mount, EdgeManager.HUB_VOLUME)],
@@ -399,10 +403,10 @@ class EdgeManager(object):
 
         edgedockerclient.copy_file_to_volume(
             EdgeManager.EDGEHUB, EdgeManager.HUB_VOLUME, EdgeManager._chain_cert(),
-            hub_mount, self.edge_cert.get_cert_file_path(EC.EDGE_CHAIN_CA))
+            hub_mount, self._edge_cert.get_cert_file_path(EC.EDGE_CHAIN_CA))
         edgedockerclient.copy_file_to_volume(
             EdgeManager.EDGEHUB, EdgeManager.HUB_VOLUME, EdgeManager._hubserver_pfx(),
-            hub_mount, self.edge_cert.get_pfx_file_path(EC.EDGE_HUB_SERVER))
+            hub_mount, self._edge_cert.get_pfx_file_path(EC.EDGE_HUB_SERVER))
         edgedockerclient.start(hubContainer.get('Id'))
 
     def _obtain_mount_path(self, edgedockerclient):
diff --git a/iotedgehubdev/utils.py b/iotedgehubdev/utils.py
index 08a04ad..937b24e 100644
--- a/iotedgehubdev/utils.py
+++ b/iotedgehubdev/utils.py
@@ -147,14 +147,8 @@ class Utils(object):
 
     @staticmethod
     @suppress_all_exceptions()
-    def hash_connection_str_hostname(connection_str):
+    def hash_connection_str_hostname(hostname):
         """Hash connection string hostname to count distint IoT Hub number"""
-        try:
-            connection_str_dict = Utils.parse_device_connection_str(connection_str)
-            hostname = connection_str_dict[EC.HOSTNAME_KEY]
-        except Exception:
-            hostname = None
-
         if not hostname:
             return ("", "")
 

diff --git a/tests/test_utils.py b/tests/test_utils.py
index f063596..69e1880 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -265,9 +265,9 @@ class TestUtilAPIs(unittest.TestCase):
         assert Utils.get_sha256_hash("foo") == "2c26b46b68ffc68ff99b453c1d30413413422d706483bfa0f98a5e886266e7ae"
 
     def test_hash_connection_str_hostname(self):
-        connection_str = "HostName=ChaoyiTestIoT.azure-devices.net;DeviceId=edge-device;SharedAccessKey=foobarbazqux="
+        hostname = "ChaoyiTestIoT.azure-devices.net"
 
-        assert Utils.hash_connection_str_hostname(connection_str) == (
+        assert Utils.hash_connection_str_hostname(hostname) == (
             '6b8fcfea09003d5f104771e83bd9ff54c592ec2277ec1815df91dd64d1633778', 'azure-devices.net')
 
         assert Utils.hash_connection_str_hostname("") == ("", "")

Provide more friendly information when starting if the user has not setup
From https://github.com/Azure/iotedgedev/pull/233#issuecomment-410917902

> @LazarusX - In start, can you automatically detect if setup hasn't been called and call it for the user?
>
> In start can you detect that it hasn't been build and let them know. The error wasn't enough to get me there. Thanks, Jon
tests/test_utils.py::TestUtilAPIs::test_hash_connection_str_hostname
tests/test_utils.py::TestUtilAPIs::test_check_if_dir_exists_returns_false_path_is_none tests/test_utils.py::TestUtilAPIs::test_get_hostname_raises_ioerror_when_getfqdn_raises_ioerror tests/test_utils.py::TestUtilAPIs::test_get_hostname_valid tests/test_utils.py::TestUtilAPIs::test_check_if_dir_exists_returns_false_if_isdir_returns_false tests/test_utils.py::TestUtilAPIs::test_delete_dir_raises_oserror_when_rmtree_fails tests/test_utils.py::TestUtilAPIs::test_delete_dir_when_dir_exists tests/test_utils.py::TestUtilAPIs::test_check_if_file_exists_returns_true tests/test_utils.py::TestUtilAPIs::test_get_sha256_hash tests/test_utils.py::TestUtilAPIs::test_mkdir_if_needed_when_dir_does_not_exist tests/test_utils.py::TestUtilAPIs::test_mkdir_if_needed_raises_oserror_when_mkdir_fails tests/test_utils.py::TestUtilAPIs::test_delete_dir_execute_onerror_callback tests/test_utils.py::TestUtilAPIs::test_check_if_file_exists_returns_false_if_exists_returns_false tests/test_utils.py::TestUtilAPIs::test_mkdir_if_needed_when_dir_exists tests/test_utils.py::TestUtilAPIs::test_check_if_file_exists_returns_false_path_is_none tests/test_utils.py::TestUtilAPIs::test_check_if_file_exists_returns_false_if_isfile_returns_false tests/test_utils.py::TestUtilAPIs::test_check_if_dir_exists_returns_true tests/test_utils.py::TestUtilAPIs::test_delete_dir_when_dir_does_not_exist tests/test_utils.py::TestUtilAPIs::test_check_if_dir_exists_returns_false_if_exists_returns_false