diff --git a/localization/Czech.json b/localization/Czech.json
index 61ff5a9..8901f0a 100644
--- a/localization/Czech.json
+++ b/localization/Czech.json
@@ -11,6 +11,9 @@
   "UploadForm_Info": "Informace o souboru",
   "UploadForm_Upload": "Nahrát",
   "UploadForm_Cancel": "Zrušit",
+  "UploadForm_NoApiKey": "Nepřidali jste API klíč. Jděte to nastavení a přidejte ho.",
+  "UploadForm_InvalidLength": "Přidali jste API klíč, ale nemá správnou délku. Měl by mít 64 znaků.",
+  "UploadForm_InvalidKey": "Špatný API klíč",
   "Message_Idle": "Nic.",
   "Message_Init": "Inicializace...",
   "Message_Check": "Kontrola...",
diff --git a/localization/English.json b/localization/English.json
index 7380548..033b08a 100644
--- a/localization/English.json
+++ b/localization/English.json
@@ -1,21 +1,24 @@
 {
-  "MainForm_DragFile": "Drag file here",
-  "MainForm_More": "More",
-  "SettingsForm_Title": "Settings",
-  "SettingsForm_General": "General settings",
-  "SettingsForm_Key": "API key",
-  "SettingsForm_Get": "Get API key",
-  "SettingsForm_Language": "Language",
-  "SettingsForm_Save": "Save",
-  "SettingsForm_Open": "Open settings file",
-  "UploadForm_Info": "File information",
-  "UploadForm_Upload": "Upload",
-  "UploadForm_Cancel": "Cancel",
-  "Message_Idle": "Idle.",
-  "Message_Init": "Initializing...",
-  "Message_Check": "Checking...",
-  "Message_Upload": "Uploading...",
-  "Message_NoLink": "No permalink found in response!",
-  "Message_NoSettings": "No settings file exists.",
-  "Message_Saved": "Settings saved."
-}
+    "MainForm_DragFile": "Drag file here",
+    "MainForm_More": "More",
+    "SettingsForm_Title": "Settings",
+    "SettingsForm_General": "General settings",
+    "SettingsForm_Key": "API key",
+    "SettingsForm_Get": "Get API key",
+    "SettingsForm_Language": "Language",
+    "SettingsForm_Save": "Save",
+    "SettingsForm_Open": "Open settings file",
+    "UploadForm_Info": "File information",
+    "UploadForm_Upload": "Upload",
+    "UploadForm_Cancel": "Cancel",
+    "UploadForm_NoApiKey": "You have not entered an API key. Please go to settings and add one.",
+    "UploadForm_InvalidLength": "You have entered an API key, but the key does not have valid length. Key should contain 64 characters.",
+    "UploadForm_InvalidKey": "Invalid API key",
+    "Message_Idle": "Idle.",
+    "Message_Init": "Initializing...",
+    "Message_Check": "Checking...",
+    "Message_Upload": "Uploading...",
+    "Message_NoLink": "No permalink found in response!",
+    "Message_NoSettings": "No settings file exists.",
+    "Message_Saved": "Settings saved."
+}
\ No newline at end of file
diff --git a/localization/French.json b/localization/French.json
index db6a381..b726bfd 100644
--- a/localization/French.json
+++ b/localization/French.json
@@ -11,6 +11,9 @@
   "UploadForm_Info": "Informations sur le fichier",
   "UploadForm_Upload": "Mettre en ligne",
   "UploadForm_Cancel": "Annuler",
+  "UploadForm_NoApiKey": "You have not entered an API key. Please go to settings and add one.",
+  "UploadForm_InvalidLength": "You have entered an API key, but the key does not have valid length. Key should contain 64 characters.",
+  "UploadForm_InvalidKey": "Invalid API key",
   "Message_Idle": "Prêt.",
   "Message_Init": "Initialisation...",
   "Message_Check": "Vérification...",
diff --git a/localization/German.json b/localization/German.json
index 9571684..83790de 100644
--- a/localization/German.json
+++ b/localization/German.json
@@ -11,6 +11,9 @@
 	"UploadForm_Info": "Dateiinformationen",
 	"UploadForm_Upload": "Hochladen",
 	"UploadForm_Cancel": "Abbrechen",
+	"UploadForm_NoApiKey": "You have not entered an API key. Please go to settings and add one.",
+    "UploadForm_InvalidLength": "You have entered an API key, but the key does not have valid length. Key should contain 64 characters.",
+    "UploadForm_InvalidKey": "Invalid API key",
 	"Message_Idle": "Leerlauf.",
 	"Message_Init": "Initialisieren ...",
 	"Message_Check": "Überprüfen ...",
diff --git a/localization/Russian.json b/localization/Russian.json
index 6696cd9..b30015e 100644
--- a/localization/Russian.json
+++ b/localization/Russian.json
@@ -11,6 +11,9 @@
   "UploadForm_Info": "Информация о файле",
   "UploadForm_Upload": "Отправить",
   "UploadForm_Cancel": "Отмена",
+  "UploadForm_NoApiKey": "You have not entered an API key. Please go to settings and add one.",
+  "UploadForm_InvalidLength": "You have entered an API key, but the key does not have valid length. Key should contain 64 characters.",
+  "UploadForm_InvalidKey": "Invalid API key",
   "Message_Idle": "Ожидание.",
   "Message_Init": "Инициализация...",
   "Message_Check": "Проверка...",
diff --git a/uploader/.vs/uploader/v16/.suo b/uploader/.vs/uploader/v16/.suo
index b27dece..f2d3185 100644
Binary files a/uploader/.vs/uploader/v16/.suo and b/uploader/.vs/uploader/v16/.suo differ
diff --git a/uploader/uploader/LocalizationBase.cs b/uploader/uploader/LocalizationBase.cs
index 7b81c6e..75ce5df 100644
--- a/uploader/uploader/LocalizationBase.cs
+++ b/uploader/uploader/LocalizationBase.cs
@@ -23,6 +23,9 @@ namespace uploader
         public string UploadForm_Info = "File information";
         public string UploadForm_Upload = "Upload";
         public string UploadForm_Cancel = "Cancel";
+        public string UploadForm_NoApiKey = "You have not entered an API key. Please go to settings and add one.";
+        public string UploadForm_InvalidLength = "You have entered an API key, but the key does not have valid length. Key should contain 64 characters.";
+        public string UploadForm_InvalidKey = "Invalid API key";
 
         public string Message_Idle = "Idle.";
         public string Message_Init = "Initializing...";
diff --git a/uploader/uploader/MainForm.cs b/uploader/uploader/MainForm.cs
index 2b47a98..662bfdd 100644
--- a/uploader/uploader/MainForm.cs
+++ b/uploader/uploader/MainForm.cs
@@ -26,6 +26,7 @@ namespace uploader
         {
             // Set working directory to exe location because of language files
             Directory.SetCurrentDirectory(Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location));
+            //LocalizationHelper.Export();
             
             var settings = Settings.LoadSettings();
             if (!string.IsNullOrEmpty(settings.Language))
diff --git a/uploader/uploader/UploadForm.cs b/uploader/uploader/UploadForm.cs
index eda5015..236ec77 100644
--- a/uploader/uploader/UploadForm.cs
+++ b/uploader/uploader/UploadForm.cs
@@ -64,6 +64,18 @@ namespace uploader
 
         private void Upload()
         {
+            if (string.IsNullOrEmpty(_settings.ApiKey))
+            {
+                MessageBox.Show(LocalizationHelper.Base.UploadForm_NoApiKey, LocalizationHelper.Base.UploadForm_InvalidKey, MessageBoxButtons.OK, MessageBoxIcon.Error);
+                return;
+            }
+
+            if (_settings.ApiKey.Length != 64)
+            {
+                MessageBox.Show(LocalizationHelper.Base.UploadForm_InvalidLength, LocalizationHelper.Base.UploadForm_InvalidKey, MessageBoxButtons.OK, MessageBoxIcon.Error);
+                return;
+            }
+            
             ChangeStatus(LocalizationHelper.Base.Message_Init);
             _client = new RestClient("https://www.virustotal.com");
             // TODO: check if file exists
diff --git a/uploader/uploader/build/anycpu.zip b/uploader/uploader/build/anycpu.zip
deleted file mode 100644
index 80e8479..0000000
Binary files a/uploader/uploader/build/anycpu.zip and /dev/null differ