diff --git a/apps/build_disk_index.cpp b/apps/build_disk_index.cpp
index b617a5f4a..759522ffe 100644
--- a/apps/build_disk_index.cpp
+++ b/apps/build_disk_index.cpp
@@ -103,13 +103,21 @@ int main(int argc, char **argv)
 
     bool use_filters = (label_file != "") ? true : false;
     diskann::Metric metric;
-    if (dist_fn == std::string("l2"))
+    if (dist_fn == std::string("l2")) 
+    {
         metric = diskann::Metric::L2;
+    }
     else if (dist_fn == std::string("mips"))
+    {
         metric = diskann::Metric::INNER_PRODUCT;
+    }
+    else if (dist_fn == std::string("cosine"))
+    {
+        metric = diskann::Metric::COSINE;
+    }
     else
     {
-        std::cout << "Error. Only l2 and mips distance functions are supported" << std::endl;
+        std::cout << "Error. Only l2, cosine, and mips distance functions are supported" << std::endl;
         return -1;
     }
 
diff --git a/src/disk_utils.cpp b/src/disk_utils.cpp
index 297619b4a..26d739f36 100644
--- a/src/disk_utils.cpp
+++ b/src/disk_utils.cpp
@@ -1239,7 +1239,9 @@ int build_disk_index(const char *dataFilePath, const char *indexFilePath, const
         augmented_labels_file = index_prefix_path + "_augmented_labels.txt";
         if (filter_threshold != 0)
         {
-            dummy_remap_file = index_prefix_path + "_dummy_remap.txt";
+            //Changing this filename to "_disk.index_dummy_map.txt" from "_dummy_map.txt" to conform 
+            //to the convention that index files all  share the _disk.index prefix.
+            dummy_remap_file = index_prefix_path + "_disk.index_dummy_map.txt";
             breakup_dense_points<T>(data_file_to_use, labels_file_to_use, filter_threshold, augmented_data_file,
                                     augmented_labels_file,
                                     dummy_remap_file); // RKNOTE: This has large memory footprint,
diff --git a/src/pq_flash_index.cpp b/src/pq_flash_index.cpp
index 11985a16f..1db76351b 100644
--- a/src/pq_flash_index.cpp
+++ b/src/pq_flash_index.cpp
@@ -876,6 +876,8 @@ template <typename T, typename LabelT> void PQFlashIndex<T, LabelT>::load_labels
 #ifndef EXEC_ENV_OLS
         infile.close();
 #endif
+        diskann::cout << "Labels file: " << labels_file << " loaded with " << num_pts_in_label_file << " points"
+                      << std::endl;
 
 #ifdef EXEC_ENV_OLS
         FileContent &content_labels_map = files.getContent(labels_map_file);
@@ -889,6 +891,8 @@ template <typename T, typename LabelT> void PQFlashIndex<T, LabelT>::load_labels
         map_reader.close();
 #endif
 
+        diskann::cout << "Labels map file: " << labels_map_file << " loaded." << std::endl;
+
 #ifdef EXEC_ENV_OLS
         if (files.fileExists(labels_to_medoids))
         {
@@ -902,7 +906,16 @@ template <typename T, typename LabelT> void PQFlashIndex<T, LabelT>::load_labels
             assert(medoid_stream.is_open());
 #endif
             load_label_medoid_map(labels_to_medoids, medoid_stream);
+            diskann::cout << "Loaded labels_to_medoids map from: " << labels_to_medoids << std::endl;
+        }
+        else
+        {
+            std::stringstream ss;
+            ss << "Filter support is enabled but " << labels_to_medoids << " file cannot be opened." << std::endl;
+            diskann::cerr << ss.str();
+            throw diskann::ANNException(ss.str(), -1);
         }
+
         std::string univ_label_file = std ::string(_disk_index_file) + "_universal_label.txt";
 
 #ifdef EXEC_ENV_OLS
@@ -944,6 +957,13 @@ template <typename T, typename LabelT> void PQFlashIndex<T, LabelT>::load_labels
 #endif
             diskann::cout << "Loaded dummy map" << std::endl;
         }
+        else
+        {
+            std::stringstream ss;
+            ss << "Note: Filter support is enabled but " << dummy_map_file << " file cannot be opened" << std::endl;
+            diskann::cerr << ss.str();
+        }
+
     }
     else
     {