diff --git a/SDWebImage/Core/SDWebImageDownloaderOperation.m b/SDWebImage/Core/SDWebImageDownloaderOperation.m
index 355e207e..9411dcac 100644
--- a/SDWebImage/Core/SDWebImageDownloaderOperation.m
+++ b/SDWebImage/Core/SDWebImageDownloaderOperation.m
@@ -140,7 +140,7 @@ typedef NSMutableDictionary<NSString *, id> SDCallbacksDictionary;
         SDWebImageDownloaderCompletedBlock completedBlock = [token valueForKey:kCompletedCallbackKey];
         dispatch_main_async_safe(^{
             if (completedBlock) {
-                completedBlock(nil, nil, [NSError errorWithDomain:SDWebImageErrorDomain code:SDWebImageErrorCancelled userInfo:nil], YES);
+                completedBlock(nil, nil, [NSError errorWithDomain:SDWebImageErrorDomain code:SDWebImageErrorCancelled userInfo:@{NSLocalizedDescriptionKey : @"Operation cancelled by user during sending the request"}], YES);
             }
         });
     }
@@ -152,7 +152,7 @@ typedef NSMutableDictionary<NSString *, id> SDCallbacksDictionary;
         if (self.isCancelled) {
             self.finished = YES;
             // Operation cancelled by user before sending the request
-            [self callCompletionBlocksWithError:[NSError errorWithDomain:SDWebImageErrorDomain code:SDWebImageErrorCancelled userInfo:nil]];
+            [self callCompletionBlocksWithError:[NSError errorWithDomain:SDWebImageErrorDomain code:SDWebImageErrorCancelled userInfo:@{NSLocalizedDescriptionKey : @"Operation cancelled by user before sending the request"}]];
             [self reset];
             return;
         }
@@ -246,8 +246,8 @@ typedef NSMutableDictionary<NSString *, id> SDCallbacksDictionary;
         if (self.isExecuting) self.executing = NO;
         if (!self.isFinished) self.finished = YES;
     }
-    // Operation cancelled by user before sending the request
-    [self callCompletionBlocksWithError:[NSError errorWithDomain:SDWebImageErrorDomain code:SDWebImageErrorCancelled userInfo:nil]];
+    // Operation cancelled by user during sending the request
+    [self callCompletionBlocksWithError:[NSError errorWithDomain:SDWebImageErrorDomain code:SDWebImageErrorCancelled userInfo:@{NSLocalizedDescriptionKey : @"Operation cancelled by user during sending the request"}]];
 
     [self reset];
 }
@@ -309,7 +309,7 @@ didReceiveResponse:(NSURLResponse *)response
         response = [self.responseModifier modifiedResponseWithResponse:response];
         if (!response) {
             valid = NO;
-            self.responseError = [NSError errorWithDomain:SDWebImageErrorDomain code:SDWebImageErrorInvalidDownloadResponse userInfo:nil];
+            self.responseError = [NSError errorWithDomain:SDWebImageErrorDomain code:SDWebImageErrorInvalidDownloadResponse userInfo:@{NSLocalizedDescriptionKey : @"Download marked as failed because response is nil"}];
         }
     }
     
@@ -323,13 +323,13 @@ didReceiveResponse:(NSURLResponse *)response
     BOOL statusCodeValid = statusCode >= 200 && statusCode < 400;
     if (!statusCodeValid) {
         valid = NO;
-        self.responseError = [NSError errorWithDomain:SDWebImageErrorDomain code:SDWebImageErrorInvalidDownloadStatusCode userInfo:@{SDWebImageErrorDownloadStatusCodeKey : @(statusCode)}];
+        self.responseError = [NSError errorWithDomain:SDWebImageErrorDomain code:SDWebImageErrorInvalidDownloadStatusCode userInfo:@{NSLocalizedDescriptionKey : @"Download marked as failed because response status code is not in 200-400", SDWebImageErrorDownloadStatusCodeKey : @(statusCode)}];
     }
     //'304 Not Modified' is an exceptional one
     //URLSession current behavior will return 200 status code when the server respond 304 and URLCache hit. But this is not a standard behavior and we just add a check
     if (statusCode == 304 && !self.cachedData) {
         valid = NO;
-        self.responseError = [NSError errorWithDomain:SDWebImageErrorDomain code:SDWebImageErrorCacheNotModified userInfo:nil];
+        self.responseError = [NSError errorWithDomain:SDWebImageErrorDomain code:SDWebImageErrorCacheNotModified userInfo:@{NSLocalizedDescriptionKey : @"Download response status code is 304 not modified and ignored"}];
     }
     
     if (valid) {
@@ -455,7 +455,7 @@ didReceiveResponse:(NSURLResponse *)response
                  *  then we should check if the cached data is equal to image data
                  */
                 if (self.options & SDWebImageDownloaderIgnoreCachedResponse && [self.cachedData isEqualToData:imageData]) {
-                    self.responseError = [NSError errorWithDomain:SDWebImageErrorDomain code:SDWebImageErrorCacheNotModified userInfo:nil];
+                    self.responseError = [NSError errorWithDomain:SDWebImageErrorDomain code:SDWebImageErrorCacheNotModified userInfo:@{NSLocalizedDescriptionKey : @"Downloaded image is not modified and ignored"}];
                     // call completion block with not modified error
                     [self callCompletionBlocksWithError:self.responseError];
                     [self done];
diff --git a/SDWebImage/Core/SDWebImageError.h b/SDWebImage/Core/SDWebImageError.h
index 3c08cc9d..e935ac97 100644
--- a/SDWebImage/Core/SDWebImageError.h
+++ b/SDWebImage/Core/SDWebImageError.h
@@ -22,5 +22,5 @@ typedef NS_ERROR_ENUM(SDWebImageErrorDomain, SDWebImageError) {
     SDWebImageErrorInvalidDownloadOperation = 2000, // The image download operation is invalid, such as nil operation or unexpected error occur when operation initialized
     SDWebImageErrorInvalidDownloadStatusCode = 2001, // The image download response a invalid status code. You can check the status code in error's userInfo under `SDWebImageErrorDownloadStatusCodeKey`
     SDWebImageErrorCancelled = 2002, // The image loading operation is cancelled before finished, during either async disk cache query, or waiting before actual network request. For actual network request error, check `NSURLErrorDomain` error domain and code.
-    SDWebImageErrorInvalidDownloadResponse = 2003, // When using response modifier, the modified download response is nil and marked as cancelled.
+    SDWebImageErrorInvalidDownloadResponse = 2003, // When using response modifier, the modified download response is nil and marked as failed.
 };
diff --git a/SDWebImage/Core/SDWebImageManager.m b/SDWebImage/Core/SDWebImageManager.m
index 4fcb0ab1..c5502cc3 100644
--- a/SDWebImage/Core/SDWebImageManager.m
+++ b/SDWebImage/Core/SDWebImageManager.m
@@ -220,7 +220,7 @@ static id<SDImageLoader> _defaultImageLoader;
             @strongify(operation);
             if (!operation || operation.isCancelled) {
                 // Image combined operation cancelled by user
-                [self callCompletionBlockForOperation:operation completion:completedBlock error:[NSError errorWithDomain:SDWebImageErrorDomain code:SDWebImageErrorCancelled userInfo:nil] url:url];
+                [self callCompletionBlockForOperation:operation completion:completedBlock error:[NSError errorWithDomain:SDWebImageErrorDomain code:SDWebImageErrorCancelled userInfo:@{NSLocalizedDescriptionKey : @"Operation cancelled by user during querying the cache"}] url:url];
                 [self safelyRemoveOperationFromRunning:operation];
                 return;
             }
@@ -269,7 +269,7 @@ static id<SDImageLoader> _defaultImageLoader;
             @strongify(operation);
             if (!operation || operation.isCancelled) {
                 // Image combined operation cancelled by user
-                [self callCompletionBlockForOperation:operation completion:completedBlock error:[NSError errorWithDomain:SDWebImageErrorDomain code:SDWebImageErrorCancelled userInfo:nil] url:url];
+                [self callCompletionBlockForOperation:operation completion:completedBlock error:[NSError errorWithDomain:SDWebImageErrorDomain code:SDWebImageErrorCancelled userInfo:@{NSLocalizedDescriptionKey : @"Operation cancelled by user during sending the request"}] url:url];
             } else if (cachedImage && options & SDWebImageRefreshCached && [error.domain isEqualToString:SDWebImageErrorDomain] && error.code == SDWebImageErrorCacheNotModified) {
                 // Image refresh hit the NSURLCache cache, do not call the completion block
             } else if ([error.domain isEqualToString:SDWebImageErrorDomain] && error.code == SDWebImageErrorCancelled) {