Unable to build WebGL builds after updating to 0.3.21

[manuelgoellnitz]

the build process fails with:

Build completed with a result of 'Failed' in 196 seconds (195942 ms) [13.01.2026 11:25:43 -> 13.01.2026 11:28:59, 3m 15s]
Building Library\Bee\artifacts\WebGL\build\debug_WebGL_wasm\build.js failed with output:

C:\workspaces\DEV SW VIS Unity\LIB SW VIS Unity UP>set MYDIR=C:\Program Files\Unity\Editor\6000.3.2f1\Editor\Data\PlaybackEngines\WebGLSupport\BuildTools\Emscripten\emscripten\

C:\workspaces\DEV SW VIS Unity\LIB SW VIS Unity UP>goto FOUND_MYDIR
Unknown option '--enable-bulk-memory-opt'
emcc: error: '"C:/Program Files/Unity/Editor/6000.3.2f1/Editor/Data/PlaybackEngines/WebGLSupport/BuildTools/Emscripten/binaryen\bin\wasm-opt" --strip-dwarf --signext-lowering --post-emscripten -O2 --low-memory-unused --zero-filled-memory --pass-arg=directize-initial-contents-immutable --strip-debug --strip-producers Library/Bee/artifacts/WebGL/build/debug_WebGL_wasm/build.wasm -o Library/Bee/artifacts/WebGL/build/debug_WebGL_wasm/build.wasm --mvp-features --enable-bulk-memory --enable-bulk-memory-opt --enable-call-indirect-overlong --enable-exception-handling --enable-multivalue --enable-mutable-globals --enable-nontrapping-float-to-int --enable-reference-types --enable-sign-ext --enable-simd' failed (returned 1)

UnityEditor.EditorApplication:Internal_CallDelayFunctions ()

[netpyoung]

Thanks for the report. The issue was confirmed to be caused by the Emscripten version during the WASM build process. This has been fixed by pinning the version and rebuilding.

Would you try to 0.3.22 ?

Log

Windows 11 - 25H2 - 6000.3.3f1 - unity.webp 0.3.21

Building Library\Bee\artifacts\WebGL\build\debug_WebGL_wasm\build.js failed with output:

D:\@unity-plugin\unity.webp\unity_project>set MYDIR=C:\Program Files\Unity\Hub\Editor\6000.3.3f1\Editor\Data\PlaybackEngines\WebGLSupport\BuildTools\Emscripten\emscripten\ 

D:\@unity-plugin\unity.webp\unity_project>goto FOUND_MYDIR 
Unknown option '--enable-bulk-memory-opt'
emcc: error: '"C:/Program Files/Unity/Hub/Editor/6000.3.3f1/Editor/Data/PlaybackEngines/WebGLSupport/BuildTools/Emscripten/binaryen\bin\wasm-opt" --strip-dwarf --signext-lowering --post-emscripten -O2 --low-memory-unused --zero-filled-memory --pass-arg=directize-initial-contents-immutable --strip-debug --strip-producers Library/Bee/artifacts/WebGL/build/debug_WebGL_wasm/build.wasm -o Library/Bee/artifacts/WebGL/build/debug_WebGL_wasm/build.wasm --mvp-features --enable-bulk-memory --enable-bulk-memory-opt --enable-call-indirect-overlong --enable-exception-handling --enable-multivalue --enable-mutable-globals --enable-nontrapping-float-to-int --enable-reference-types --enable-sign-ext --enable-simd' failed (returned 1)

UnityEditor.EditorApplication:Internal_CallDelayFunctions ()



---------------


Build completed with a result of 'Failed' in 208 seconds (208149 ms) [1/13/2026 8:51:25 PM -> 1/13/2026 8:54:53 PM, 3m 28s]
Building Library\Bee\artifacts\WebGL\build\debug_WebGL_wasm\build.js failed with output:

D:\@unity-plugin\unity.webp\unity_project>set MYDIR=C:\Program Files\Unity\Hub\Editor\6000.3.3f1\Editor\Data\PlaybackEngines\WebGLSupport\BuildTools\Emscripten\emscripten\ 

D:\@unity-plugin\unity.webp\unity_project>goto FOUND_MYDIR 
Unknown option '--enable-bulk-memory-opt'
emcc: error: '"C:/Program Files/Unity/Hub/Editor/6000.3.3f1/Editor/Data/PlaybackEngines/WebGLSupport/BuildTools/Emscripten/binaryen\bin\wasm-opt" --strip-dwarf --signext-lowering --post-emscripten -O2 --low-memory-unused --zero-filled-memory --pass-arg=directize-initial-contents-immutable --strip-debug --strip-producers Library/Bee/artifacts/WebGL/build/debug_WebGL_wasm/build.wasm -o Library/Bee/artifacts/WebGL/build/debug_WebGL_wasm/build.wasm --mvp-features --enable-bulk-memory --enable-bulk-memory-opt --enable-call-indirect-overlong --enable-exception-handling --enable-multivalue --enable-mutable-globals --enable-nontrapping-float-to-int --enable-reference-types --enable-sign-ext --enable-simd' failed (returned 1)

UnityEditor.EditorApplication:Internal_CallDelayFunctions ()

[manuelgoellnitz]

Yes it is fixed in 0.3.22

Thx!