How to resolve Missing Protobuf Libraries and Linker Errors during packaging?

Question

I am trying to package my Unreal Engine project for Android using Unreal Engine 5.4. The project includes the Convai plugin, which depends on gRPC and Protobuf. However, during packaging, I encounter the following linker error:

Error Message:

`Android (ASTC)): InstalledDir: C:/Users/iassi/AppData/Local/Android/Sdk/ndk/26.1.10909125/toolchains/llvm/prebuilt/windows-x86_64/bin
UATHelper: Packaging (Android (ASTC)): NDK toolchain: r26b, NDK version: 260200, ClangVersion: 17.0.2
UATHelper: Packaging (Android (ASTC)): Compiling Native 64-bit code with NDK API 'android-34'
UATHelper: Packaging (Android (ASTC)): Link: C:\Users\iassi\AppData\Local\Android\Sdk\ndk\26.1.10909125\toolchains\llvm\prebuilt\windows-x86_64\bin\clang++.exe  -static-libstdc++ -no-canonical-prefixes -shared -Wl,-Bsymbolic -Wl,--no-undefined -Wl,--gc-sections --target=aarch64-none-linux-android34 --gcc-toolchain="C:/Users/iassi/AppData/Local/Android/Sdk/ndk/26.1.10909125/toolchains/llvm/prebuilt/windows-x86_64" --sysroot="C:/Users/iassi/AppData/Local/Android/Sdk/ndk/26.1.10909125/toolchains/llvm/prebuilt/windows-x86_64/sysroot" -DANDROID=1 -march=armv8-a -Wl,-no-pie -fuse-ld=lld -Wl,-soname,
libUnreal.so -Wl,--build-id=sha1 -Wl,--pack-dyn-relocs=android+relr,--use-android-relr-tags -Wl,--hash-style=gnu -z max-page-size=65536 -o "C:/Users/iassi/OneDrive/Documents/Unreal Projects/test3/Binaries/Android/test3-arm64.so" @"C:/Users/iassi/OneDrive/Documents/Unreal Projects/test3/Intermediate/Build/Android/a/test3/Development/test3-arm64.so.rsp"
UATHelper: Packaging (Android (ASTC)): Link: C:\Users\iassi\AppData\Local\Android\Sdk\ndk\26.1.10909125\toolchains\llvm\prebuilt\windows-x86_64\bin\clang++.exe  -static-libstdc++ -no-canonical-prefixes -shared -Wl,-Bsymbolic -Wl,--no-undefined -Wl,--gc-sections --target=x86_64-none-linux-android34 --gcc-toolchain="C:/Users/iassi/AppData/Local/Android/Sdk/ndk/26.1.10909125/toolchains/llvm/prebuilt/windows-x86_64" --sysroot="C:/Users/iassi/AppData/Local/Android/Sdk/ndk/26.1.10909125/toolchains/llvm/prebuilt/windows-x86_64/sysroot" -DANDROID=1 -march=atom -Wl,-no-pie -fuse-ld=lld -Wl,-soname,libU
nreal.so -Wl,--build-id=sha1 -Wl,--pack-dyn-relocs=android+relr,--use-android-relr-tags -Wl,--hash-style=gnu -z max-page-size=65536 -o "C:/Users/iassi/OneDrive/Documents/Unreal Projects/test3/Binaries/Android/test3-x64.so" @"C:/Users/iassi/OneDrive/Documents/Unreal Projects/test3/Intermediate/Build/Android/x/test3/Development/test3-x64.so.rsp"
UATHelper: Packaging (Android (ASTC)): Writing manifest to C:\Users\iassi\OneDrive\Documents\Unreal Projects\test3\Intermediate\Build\Manifest.xml
UATHelper: Packaging (Android (ASTC)): Building test3...
UATHelper: Packaging (Android (ASTC)): [Adaptive Build] Excluded from test3 unity file: test3.cpp
UATHelper: Packaging (Android (ASTC)): Determining max actions to execute in parallel (14 physical cores, 20 logical cores)
UATHelper: Packaging (Android (ASTC)):   Executing up to 14 processes, one per physical core
UATHelper: Packaging (Android (ASTC)):   Requested 1.5 GB memory per action, 728.52 MB available: limiting max parallel actions to 1
UATHelper: Packaging (Android (ASTC)): Using Parallel executor to run 7 action(s)
UATHelper: Packaging (Android (ASTC)): ------ Building 7 action(s) started ------
UATHelper: Packaging (Android (ASTC)): [1/7] Compile [arm64] SharedPCH.Core.Project.ValApi.Cpp20.h
UATHelper: Packaging (Android (ASTC)): [2/7] Compile [x64] SharedPCH.Core.Project.ValApi.Cpp20.h
UATHelper: Packaging (Android (ASTC)): [3/7] Compile [arm64] test3.cpp
UATHelper: Packaging (Android (ASTC)): [4/7] clang++ test3-arm64.so
UATHelper: Packaging (Android (ASTC)): [5/7] Compile [x64] test3.cpp
UATHelper: Packaging (Android (ASTC)): [6/7] clang++ test3-x64.so
UATHelper: Packaging (Android (ASTC)): ld.lld: error: undefined symbol: google::protobuf::io::StringOutputStream::StringOutputStream(std::__ndk1::basic_string<char, std::__ndk1::char_traits<char>, std::__ndk1::allocator<char>>*)
UATHelper: Packaging (Android (ASTC)): >>> referenced by csharp_generator.cc:778 (C:/Storage/Software/Tools/gRPC/Convai_grpc/grpc/src/compiler/csharp_generator.cc:778)
UATHelper: Packaging (Android (ASTC)): >>>               csharp_generator.cc.o:(grpc_csharp_generator::GetServices(google::protobuf::FileDescriptor const*, bool, bool, bool)) in archive C:/Program Files/Epic Games/ext/UE_5.4/Engine/Plugins/Marketplace/Convai/Source/ThirdParty/gRPC/lib/android/x86_64/libgrpc_plugin_support.a
UATHelper: Packaging (Android (ASTC)): ld.lld: error: undefined symbol: google::protobuf::io::Printer::Printer(google::protobuf::io::ZeroCopyOutputStream*, char)
UATHelper: Packaging (Android (ASTC)): >>> referenced by csharp_generator.cc:779 (C:/Storage/Software/Tools/gRPC/Convai_grpc/grpc/src/compiler/csharp_generator.cc:779)
UATHelper: Packaging (Android (ASTC)): >>>               csharp_generator.cc.o:(grpc_csharp_generator::GetServices(google::protobuf::FileDescriptor const*, bool, bool, bool)) in archive C:/Program Files/Epic Games/ext/UE_5.4/Engine/Plugins/Marketplace/Convai/Source/ThirdParty/gRPC/lib/android/x86_64/libgrpc_plugin_support.a
UATHelper: Packaging (Android (ASTC)): ld.lld: error: undefined symbol: google::protobuf::io::Printer::Print(std::__ndk1::map<std::__ndk1::basic_string<char, std::__ndk1::char_traits<char>, std::__ndk1::allocator<char>>, std::__ndk1::basic_string<char, std::__ndk1::char_traits<char>, std::__ndk1::allocator<char>>, std::__ndk1::less<std::__ndk1::basic_string<char, std::__ndk1::char_traits<char>, std::__ndk1::allocator<char>>>, std::__ndk1::allocator<std::__ndk1::pair<std::__ndk1::basic_string<char, std::__ndk1::char_traits<char>, std::__ndk1::allocator<char>> const, std::__ndk1::basic_string<ch
ar, std::__ndk1::char_traits<char>, std::__ndk1::allocator<char>>>>> const&, char const*)`

What I've Tried: Checking the Convai Plugin Folder:

The plugin's Source/ThirdParty/gRPC/lib/android/ directory lacks the required protobuf static libraries (libprotobuf.a, libprotobuf-lite.a, and libprotoc.a) for Android architectures like arm64-v8a. Searching for Precompiled Protobuf Libraries:

I checked the Protobuf GitHub releases, but they only offer precompiled libraries for desktop platforms (Linux, macOS, Windows). Android libraries are not included.

Attempting to Modify platforms.json:

I updated my platforms.json file to include API Level 34, but this didn’t resolve the packaging issue.

Rebuilding Project:

Cleared Intermediate and Saved folders and rebuilt the project multiple times.

Environment Details:

Unreal Engine Version: 5.4
Android NDK Version: r26b
Target API Level: android-34
Convai Plugin Version: Latest (as of November 2024)
Protobuf Version: Need at least v3.21 to match gRPC.

How can I resolve the linker errors and obtain or build the missing protobuf libraries (libprotobuf.a, libprotobuf-lite.a, libprotoc.a) for Android architectures like arm64-v8a?
Could the issue be related to mismatched NDK versions or Protobuf configurations?

Any guidance, detailed steps, or examples would be greatly appreciated!