Add an error message when authentication fails

resources/language/resource.language.en_gb/strings.po

@@ -1104,3 +1104,7 @@ msgstr "Login using Quick Connect"
 msgctxt "#30445"
 msgid "Continue Watching"
 msgstr "Continue Watching"
+
+msgctxt "#30446"
+msgid "There was an error logging in"
+msgstr "There was an error logging in"

resources/lib/server_detect.py

@@ -260,6 +260,12 @@ def check_server(force=False, change_user=False, notify=False):
 
                 auth_payload = {'username': selected_user_name, 'pw': password}
                 auth = api.authenticate(auth_payload)
+                if not auth:
+                    # Login failed, we don't want to change anything
+                    something_changed = False
+                    log.info('There was an error logging in with user {}'.format(selected_user_name))
+                    xbmcgui.Dialog().ok(__addon_name__, translate_string(30446))
+
 
         if something_changed:
             home_window = HomeWindow()