diff --git a/android/app/src/main/java/com/blackforestbytes/simplecloudnotifier/model/ServerCommunication.java b/android/app/src/main/java/com/blackforestbytes/simplecloudnotifier/model/ServerCommunication.java
index 6c87f0d..05d0240 100644
--- a/android/app/src/main/java/com/blackforestbytes/simplecloudnotifier/model/ServerCommunication.java
+++ b/android/app/src/main/java/com/blackforestbytes/simplecloudnotifier/model/ServerCommunication.java
@@ -246,8 +246,27 @@ public class ServerCommunication
 
                         JSONObject json = (JSONObject) new JSONTokener(r).nextValue();
 
-                        if (!json.getBoolean("success")) {
+                        if (!json.getBoolean("success"))
+                        {
                             SCNApp.showToast(json.getString("message"), 4000);
+
+                            int errid = json.optInt("errid", 0);
+
+                            if (errid == 201 || errid == 202 || errid == 203 || errid == 204)
+                            {
+                                // user not found or auth failed
+
+                                SCNSettings.inst().user_id          = -1;
+                                SCNSettings.inst().user_key         = "";
+                                SCNSettings.inst().quota_curr       = 0;
+                                SCNSettings.inst().quota_max        = 0;
+                                SCNSettings.inst().promode_server   = false;
+                                SCNSettings.inst().fcm_token_server = "";
+                                SCNSettings.inst().save();
+
+                                SCNApp.refreshAccountTab();
+                            }
+
                             return;
                         }
 
diff --git a/web/schema.sql b/web/schema.sql
index ec0fd5e..acf2653 100644
--- a/web/schema.sql
+++ b/web/schema.sql
@@ -1,3 +1,4 @@
+DROP TABLE IF EXISTS `users`;
 CREATE TABLE `users`
 (
 	`user_id`            INT(11)         NOT NULL   AUTO_INCREMENT,
@@ -16,6 +17,7 @@ CREATE TABLE `users`
 	PRIMARY KEY (`user_id`)
 );
 
+DROP TABLE IF EXISTS `messages`;
 CREATE TABLE `messages`
 (
 	`scn_message_id`     INT(11)         NOT NULL   AUTO_INCREMENT,
@@ -31,4 +33,4 @@ CREATE TABLE `messages`
 	`usr_message_id`     VARCHAR(256)        NULL,
 
 	PRIMARY KEY (`scn_message_id`)
-)
\ No newline at end of file
+);
\ No newline at end of file