diff --git a/features.md b/features.md
index 01f2e51..be7d9d3 100644
--- a/features.md
+++ b/features.md
@@ -304,6 +304,24 @@ Download directly from your favorited artists and posts on Kemono.su.
         -   Summary statistics at the end of a session (total downloaded, skipped, failed).
 
 ---
+## Error Handling & Retries
+
+-   **🆘 Error Button (Main UI):**
+    -   **Location:** Typically near the main action buttons (e.g., Start, Pause, Cancel).
+    -   **Purpose:** Becomes active if files failed to download during the last session (and were not successfully retried). Clicking it opens the "Files Skipped Due to Errors" dialog.
+    -   **"Files Skipped Due to Errors" Dialog:**
+        -   **File List:** Displays a list of files that encountered download errors. Each entry shows the filename, the post it was from (title and ID).
+        -   **Checkboxes:** Allows selection of individual files from the list.
+        -   **"Select All" Button:** Checks all files in the list.
+        -   **"Retry Selected" Button:** Attempts to re-download all checked files.
+        -   **"Export URLs to .txt" Button:**
+            -   Opens an "Export Options" dialog.
+            -   **"Link per line (URL only)":** Exports only the direct download URL for each failed file, one URL per line.
+            -   **"Export with details (URL [Post, File info])":** Exports the URL followed by details like Post Title, Post ID, and Original Filename in brackets.
+            -   Prompts the user to save the generated `.txt` file.
+        -   **"OK" Button:** Closes the dialog.
+    -   **Note:** Files successfully retried or skipped due to hash match during a retry attempt are removed from this error list.
+---
 
 ## Other UI Elements
 
diff --git a/main.py b/main.py
index 35be0c5..5ddabe0 100644
--- a/main.py
+++ b/main.py
@@ -2045,7 +2045,7 @@ class TourDialog (QDialog ):
 
     CONFIG_ORGANIZATION_NAME ="KemonoDownloader"
     CONFIG_APP_NAME_TOUR ="ApplicationTour"
-    TOUR_SHOWN_KEY ="neverShowTourAgainV16"
+    TOUR_SHOWN_KEY ="neverShowTourAgainV17"
 
     def __init__ (self ,parent =None ):
         super ().__init__ (parent )
diff --git a/readme.md b/readme.md
index 57be133..9dd8237 100644
--- a/readme.md
+++ b/readme.md
@@ -1,4 +1,4 @@
-<h1 align="center">Kemono Downloader v5.0.0</h1>
+<h1 align="center">Kemono Downloader v5.1.0</h1>
 
 <table align="center">
   <tr>
@@ -34,7 +34,7 @@ A powerful, feature-rich GUI application for downloading content from **[Kemono.
 Built with PyQt5, this tool is designed for users who want deep filtering capabilities, customizable folder structures, efficient downloads, and intelligent automation, all within a modern and user-friendly graphical interface.
 
 *This v5.0.0 release marks a significant feature milestone. Future updates are expected to be less frequent, focusing on maintenance and minor refinements.*
-
+*Update v5.1.0 enhances error handling and UI responsiveness.*
 <p align="center">
   <a href="features.md"><strong>📚 Full Feature List</strong></a> • 
   <a href="LICENSE"><strong>📝 License</strong></a>
@@ -78,6 +78,14 @@ Kemono Downloader offers a range of features to streamline your content download
 
 ---
 
+## ✨ What's New in v5.1.0
+-   **Enhanced Error File Management**: The "Error" button now opens a dialog listing files that failed to download. This dialog includes:
+    -   An option to **retry selected** failed downloads.
+    -   A new **"Export URLs to .txt"** button, allowing users to save links of failed downloads either as "URL only" or "URL with details" (including post title, ID, and original filename).
+    -   Fixed a bug where files skipped during retry (due to existing hash match) were not correctly removed from the error list.
+-   **Improved UI Stability**: Addressed issues with UI state management to more accurately reflect ongoing download activities (including retries and external link downloads). This prevents the "Cancel" button from becoming inactive prematurely while operations are still running.
+---
+
 ## Installation
 
 ### Requirements