diff --git a/sdk/src/vtx_reader/src/vtx/reader/formatters/flatbuffer_reader_policy.cpp b/sdk/src/vtx_reader/src/vtx/reader/formatters/flatbuffer_reader_policy.cpp
index c0879d3..d1b6c4f 100644
--- a/sdk/src/vtx_reader/src/vtx/reader/formatters/flatbuffer_reader_policy.cpp
+++ b/sdk/src/vtx_reader/src/vtx/reader/formatters/flatbuffer_reader_policy.cpp
@@ -53,10 +53,16 @@ void VTX::FlatBuffersReaderPolicy::ProcessChunkData(int chunk_index, const std::
     for (size_t i = 0; i < num_frames; ++i) {
         if (st.stop_requested())
             return;
-        VTX::Serialization::FromFlat(chunk->frames()->Get(i), out_native_frames[i]);
+        const auto* frame_fb = chunk->frames()->Get(i);
+        VTX::Serialization::FromFlat(frame_fb, out_native_frames[i]);
 
-        //pack for differ
-        auto* data_obj = chunk->frames()->Get(i)->data()->Get(0);
+        //pack bucket 0 for the differ; a frame with no buckets contributes an empty span
+        const auto* frame_buckets = frame_fb->data();
+        if (!frame_buckets || frame_buckets->size() == 0) {
+            frame_sizes.push_back(0);
+            continue;
+        }
+        auto* data_obj = frame_buckets->Get(0);
         std::unique_ptr<fbsvtx::BucketT> dataT(data_obj->UnPack());
 
         fbb.Clear();
diff --git a/sdk/src/vtx_reader/src/vtx/reader/formatters/protobuff_reader_policy.cpp b/sdk/src/vtx_reader/src/vtx/reader/formatters/protobuff_reader_policy.cpp
index 2af17ee..e575ce5 100644
--- a/sdk/src/vtx_reader/src/vtx/reader/formatters/protobuff_reader_policy.cpp
+++ b/sdk/src/vtx_reader/src/vtx/reader/formatters/protobuff_reader_policy.cpp
@@ -42,7 +42,9 @@ void VTX::ProtobufReaderPolicy::ProcessChunkData(int chunk_index, const std::str
     //precalculate data size
     size_t total_raw_size = 0;
     for (int i = 0; i < num_frames; ++i) {
-        total_raw_size += proto.frames(i).data(0).ByteSizeLong();
+        if (proto.frames(i).data_size() > 0) {
+            total_raw_size += proto.frames(i).data(0).ByteSizeLong();
+        }
     }
     out_decompressed_blob.reserve(total_raw_size);
 
@@ -55,8 +57,11 @@ void VTX::ProtobufReaderPolicy::ProcessChunkData(int chunk_index, const std::str
             return;
         Serialization::FromProto(proto.frames(i), out_native_frames[i]);
 
-        // Eextract root for the differ
-        std::string rawBytes = proto.frames(i).data(0).SerializeAsString();
+        // Extract bucket 0 for the differ; a frame with no buckets contributes an empty span
+        std::string rawBytes;
+        if (proto.frames(i).data_size() > 0) {
+            rawBytes = proto.frames(i).data(0).SerializeAsString();
+        }
         out_decompressed_blob.insert(out_decompressed_blob.end(), rawBytes.begin(), rawBytes.end());
         frame_sizes.push_back(rawBytes.size());
     }