Common Issues and Solutions

This section addresses common issues encountered when porting Unity games to WebGL for the spawnd platform, with specific solutions for Unity 2022 LTS and later versions.

---

Memory-Related Issues

Issue: Out of Memory Errors

Description: The WebGL build runs out of memory, especially on 32-bit browsers or mobile devices.

Solution:

• Implementation:
  1. Configure appropriate memory settings in Player Settings
  2. Enable memory growth in WebGL Publishing Settings
  3. Reduce initial heap size for faster startup
  4. Use Addressables to load assets on demand
  5. Implement object pooling to reduce garbage collection

Code Example:

// Configure memory settings via script
PlayerSettings.WebGL.memorySize = 512; // Set initial memory in MB
PlayerSettings.WebGL.linkerTarget = WebGLLinkerTarget.Wasm; // Use WebAssembly
PlayerSettings.WebGL.threadsSupport = false; // Disable threading for broader compatibility

Issue: Memory Leaks

Description: Memory usage continuously increases during gameplay, eventually causing crashes.

Solution:

• Implementation:
  1. Use the Memory Profiler to identify leaks
  2. Properly unload unused assets and scenes
  3. Implement proper Addressables reference counting
  4. Avoid creating temporary objects in frequently called methods
  5. Use object pooling for frequently instantiated and destroyed objects

Code Example:

// Proper Addressables cleanup
AsyncOperationHandle<GameObject> handle = Addressables.LoadAssetAsync<GameObject>("assetAddress");
// Use the asset...
Addressables.Release(handle); // Always release when done

---

Performance Issues

Issue: Slow Initial Loading

Description: WebGL builds take too long to initially load, causing users to abandon the game.

Solution:

• Implementation:
  1. Use Brotli compression (Unity 2022 LTS feature)
  2. Enable Data Caching in Publishing Settings
  3. Implement a progressive loading screen with visual feedback
  4. Use the Code Optimization "Disk Size with LTO" setting for release builds
  5. Split content using Addressables to reduce initial download size

Code Example:

// Configure compression settings
PlayerSettings.WebGL.compressionFormat = WebGLCompressionFormat.Brotli;
PlayerSettings.WebGL.dataCaching = true;

Issue: Runtime Performance Stuttering

Description: Game experiences frequent frame drops and stuttering during gameplay.

Solution:

• Implementation:
  1. Use the WebGL 2.0 API for better performance
  2. Implement texture streaming to reduce memory pressure
  3. Reduce draw calls by batching similar materials
  4. Use the Universal Render Pipeline with optimized settings
  5. Avoid complex physics calculations in Update methods

Code Example:

// Check if WebGL 2.0 is available at runtime
if (SystemInfo.graphicsDeviceType == GraphicsDeviceType.OpenGLES3)
{
    // WebGL 2.0 is available, enable advanced features
}
else
{
    // Fall back to simpler rendering
}

---

Compatibility Issues

Issue: Browser Compatibility Problems

Description: Game works in some browsers but not others, or behaves inconsistently across browsers.

Solution:

• Implementation:
  1. Test on multiple browsers during development
  2. Use feature detection instead of browser detection
  3. Implement fallbacks for unsupported features
  4. Avoid browser-specific APIs without proper checks
  5. Use Unity's built-in input system for consistent behavior

Code Example:

// Check for WebGL compatibility at runtime
void CheckWebGLCompatibility()
{
    #if UNITY_WEBGL && !UNITY_EDITOR
    // Check for specific features
    WebGLInput.captureAllKeyboardInput = true;
    #endif
}

---

Asset Loading Issues

Issue: AssetBundle Compression Errors

Description: Error message: "Decompressing this format (1) isn't supported on this platform"

Solution:

• Implementation:
  1. Use LZ4 compression for AssetBundles instead of LZMA
  2. For Addressables, configure the correct compression in the Addressables Groups window
  3. Avoid using LZMA compression for any content loaded at runtime

Code Example:

// Configure AssetBundle compression
BuildPipeline.BuildAssetBundles(outputPath, BuildAssetBundleOptions.ChunkBasedCompression, BuildTarget.WebGL);

Issue: Missing or Broken Assets

Description: Some assets fail to load or appear broken in WebGL builds.

Solution:

• Implementation:
  1. Check texture compression settings (use ASTC for WebGL 2.0)
  2. Ensure all asset paths use forward slashes (/)
  3. Implement error handling for asset loading
  4. Test with different compression settings
  5. Use Addressables for better asset management

---

Build and Deployment Issues

Issue: Incorrect Header Check Error

Description: Browser console shows "Incorrect header check" error when loading the game.

Solution:

• Implementation:
  1. Configure server to serve compressed files with correct MIME types and headers
  2. For Brotli compression, ensure Content-Encoding: br header
  3. For Gzip compression, ensure Content-Encoding: gzip header
  4. Use .htaccess file for Apache servers or web.config for IIS

Example .htaccess Configuration:

# For Brotli compressed files
<Files *.js.br>
  AddType application/javascript .br
  AddEncoding br .br
</Files>
<Files *.data.br>
  AddType application/octet-stream .br
  AddEncoding br .br
</Files>
<Files *.wasm.br>
  AddType application/wasm .br
  AddEncoding br .br
</Files>

Issue: Build Fails with Emscripten Errors

Description: WebGL build fails with Emscripten-related errors, particularly after upgrading Unity.

Solution:

• Implementation:
  1. Delete the Library/Bee folder and rebuild
  2. Ensure native plugins are compatible with the current Emscripten version
  3. For custom plugins, rebuild them with the matching Emscripten version
  4. Check for C++ code that might be incompatible with WebAssembly