diff --git a/onionshare/__init__.py b/onionshare/__init__.py
index cec1daa5..8de8fa16 100644
--- a/onionshare/__init__.py
+++ b/onionshare/__init__.py
@@ -155,7 +155,7 @@ def main(cwd=None):
         app = OnionShare(debug, local_only, stay_open, transparent_torification, stealth)
         app.choose_port()
         app.start_onion_service()
-    except (onion.TorTooOld, onion.TorErrorInvalidSetting, onion.TorErrorAutomatic, onion.TorErrorSocketPort, onion.TorErrorSocketFile, onion.TorErrorMissingPassword, onion.TorErrorUnreadableCookieFile) as e:
+    except (onion.TorTooOld, onion.TorErrorInvalidSetting, onion.TorErrorAutomatic, onion.TorErrorSocketPort, onion.TorErrorSocketFile, onion.TorErrorMissingPassword, onion.TorErrorUnreadableCookieFile, onion.TorErrorAuthError) as e:
         sys.exit(e.args[0])
     except KeyboardInterrupt:
         print("")
diff --git a/onionshare/onion.py b/onionshare/onion.py
index 2e3c9211..4fd5e5c9 100644
--- a/onionshare/onion.py
+++ b/onionshare/onion.py
@@ -20,7 +20,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 from stem.control import Controller
 from stem import SocketError
-from stem.connection import MissingPassword, UnreadableCookieFile
+from stem.connection import MissingPassword, UnreadableCookieFile, AuthenticationFailure
 import os, sys, tempfile, shutil, urllib, platform
 
 from . import socks
@@ -65,6 +65,13 @@ class TorErrorUnreadableCookieFile(Exception):
     """
     pass
 
+class TorErrorAuthError(Exception):
+    """
+    OnionShare connected to the address and port, but can't authenticate. It's possible
+    that a Tor controller isn't listening on this port.
+    """
+    pass
+
 class TorTooOld(Exception):
     """
     This exception is raised if onionshare needs to use a feature of Tor or stem
@@ -180,12 +187,13 @@ class Onion(object):
                 else:
                     raise TorErrorInvalidSetting(strings._("settings_error_unknown"))
 
-            except SocketError:
+            except:
                 if self.settings.get('connection_type') == 'control_port':
                     raise TorErrorSocketPort(strings._("settings_error_socket_port").format(self.settings.get('control_port_address'), self.settings.get('control_port_port')))
                 else:
                     raise TorErrorSocketFile(strings._("settings_error_socket_file").format(self.settings.get('socket_file_path')))
 
+
             # Try authenticating
             try:
                 if self.settings.get('auth_type') == 'no_auth':
@@ -199,6 +207,8 @@ class Onion(object):
                 raise TorErrorMissingPassword(strings._('settings_error_missing_password'))
             except UnreadableCookieFile:
                 raise TorErrorUnreadableCookieFile(strings._('settings_error_unreadable_cookie_file'))
+            except AuthenticationFailure:
+                raise TorErrorAuthError(strings._('settings_error_auth').format(self.settings.get('control_port_address'), self.settings.get('control_port_port')))
 
         # get the tor version
         self.tor_version = self.c.get_version().version_str
diff --git a/onionshare_gui/__init__.py b/onionshare_gui/__init__.py
index 8fb9474d..a49a0b7c 100644
--- a/onionshare_gui/__init__.py
+++ b/onionshare_gui/__init__.py
@@ -177,7 +177,7 @@ class OnionShareGui(QtWidgets.QMainWindow):
                 self.app.start_onion_service()
                 self.starting_server_step2.emit()
 
-            except (onionshare.onion.TorTooOld, onionshare.onion.TorErrorInvalidSetting, onionshare.onion.TorErrorAutomatic, onionshare.onion.TorErrorSocketPort, onionshare.onion.TorErrorSocketFile, onionshare.onion.TorErrorMissingPassword, onionshare.onion.TorErrorUnreadableCookieFile) as e:
+            except (onionshare.onion.TorTooOld, onionshare.onion.TorErrorInvalidSetting, onionshare.onion.TorErrorAutomatic, onionshare.onion.TorErrorSocketPort, onionshare.onion.TorErrorSocketFile, onionshare.onion.TorErrorMissingPassword, onionshare.onion.TorErrorUnreadableCookieFile, onionshare.onion.TorErrorAuthError) as e:
                 self.starting_server_error.emit(e.args[0])
                 return
 
diff --git a/onionshare_gui/settings_dialog.py b/onionshare_gui/settings_dialog.py
index 1c08b26c..8db649f8 100644
--- a/onionshare_gui/settings_dialog.py
+++ b/onionshare_gui/settings_dialog.py
@@ -21,7 +21,7 @@ from PyQt5 import QtCore, QtWidgets, QtGui
 
 from onionshare import strings
 from onionshare.settings import Settings
-from onionshare.onion import Onion, TorErrorInvalidSetting, TorErrorAutomatic, TorErrorSocketPort, TorErrorSocketFile, TorErrorMissingPassword, TorErrorUnreadableCookieFile
+from onionshare.onion import Onion, TorErrorInvalidSetting, TorErrorAutomatic, TorErrorSocketPort, TorErrorSocketFile, TorErrorMissingPassword, TorErrorUnreadableCookieFile, TorErrorAuthError
 
 from .alert import Alert
 
@@ -216,7 +216,7 @@ class SettingsDialog(QtWidgets.QDialog):
             # If an exception hasn't been raised yet, the Tor settings work
             Alert(strings._('settings_test_success', True).format(onion.tor_version, onion.supports_ephemeral, onion.supports_stealth))
 
-        except (TorErrorInvalidSetting, TorErrorAutomatic, TorErrorSocketPort, TorErrorSocketFile, TorErrorMissingPassword, TorErrorUnreadableCookieFile) as e:
+        except (TorErrorInvalidSetting, TorErrorAutomatic, TorErrorSocketPort, TorErrorSocketFile, TorErrorMissingPassword, TorErrorUnreadableCookieFile, TorErrorAuthError) as e:
             Alert(e.args[0], QtWidgets.QMessageBox.Warning)
 
     def save_clicked(self):
diff --git a/resources/locale/en.json b/resources/locale/en.json
index 1d222a20..74fe4739 100644
--- a/resources/locale/en.json
+++ b/resources/locale/en.json
@@ -77,8 +77,9 @@
     "settings_saved": "Settings saved to {}",
     "settings_error_unknown": "Can't connect to Tor controller because the settings don't make sense.",
     "settings_error_automatic": "Can't connect to Tor controller. Is Tor Browser running in the background? If you don't have it you can get it from:\nhttps://www.torproject.org/.",
-    "settings_error_socket_port": "Can't connect to Tor controller on address {} with port {}.",
+    "settings_error_socket_port": "Can't connect to Tor controller on {}:{}.",
     "settings_error_socket_file": "Can't connect to Tor controller using socket file {}.",
+    "settings_error_auth": "Connected to {}:{}, but can't authenticate. Maybe this isn't a Tor controller?",
     "settings_error_missing_password": "Connected to Tor controller, but it requires a password to authenticate.",
     "settings_error_unreadable_cookie_file": "Connected to Tor controller, but can't authenticate because your password may be wrong, and your user doesn't have permission to read the cookie file.",
     "settings_test_success": "Congratulations, OnionShare can connect to the Tor controller.\n\nTor version: {}\nSupports ephemeral onion services: {}\nSupports stealth onion services: {}"