Assertion `!nested' failed.

[palan1204]

I am getting Notnested assertion when i try to serialization of vector of vectors
Here is my serialization code Not sure what went wrong.

const auto bufferSize = static_cast<uint32_t>(bufferEnd - bufferStart);
flatbuffers::FlatBufferBuilder builder;
bool isSerialised = false;

try
{
    const AABMessageNewBaseTablesNotification& msg = dynamic_cast<const AABMessageNewBaseTablesNotification&>(message);
    
    // Move the creation of sub-objects above the FlatBufferBuilder construction
    std::vector<flatbuffers::Offset<AAB::UpdatedBDTList>> updatedBDTListVector;
    const auto& updatedBDTList = msg.GetUpdatedBDTList();
    
    for (const auto& pair : updatedBDTList)
    {
        auto TableList = VectorToFlatBufferVector(pair.second, builder);
        auto ServiceName  = builder.CreateString(pair.first);
        updatedBDTListVector.push_back(AAB::CreateUpdatedBDTList(builder, ServiceName, TableList));
    }
    
    AAB::AABMessageNewBaseDataTablesNotificationBuilder messageBuilder(builder);
    messageBuilder.add_type(msg.Type());
    messageBuilder.add_version(msg.Version());
    messageBuilder.add_updatedBDTList(builder.CreateVector(updatedBDTListVector));
    
    auto messageOffset = messageBuilder.Finish();
    builder.Finish(messageOffset);
    
    auto size = builder.GetSize();
    messageSize = size;
    
    if (size <= bufferSize) {
        auto span = builder.GetBufferPointer();  // Use GetBufferPointer instead of GetBufferSpan
        std::copy(span, span + size, bufferStart);
        isSerialised = (size != 0);
    }
}
catch (const std::bad_cast&)
{
}

builder.Clear();
return isSerialised;

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