-repro: see title
--only test on Windows so far
--works for Windows Standalone IL2CPP builds

-repro:
--create a new project on a partition where the editor isn't installed
--try building the project for WebGL
--NOTICE it fails with an error:

##### CommandLine
cd "E:/Unity Installs/2021.2/2021.2.0a18/Editor/Data/PlaybackEngines/WebGLSupport/BuildTools" && "E:/Unity Installs/2021.2/2021.2.0a18/Editor/Data/Tools/nodejs/node.exe" "E:/Unity Installs/2021.2/2021.2.0a18/Editor/Data/PlaybackEngines/WebGLSupport/BuildTools/Preprocess.js" "locals.inputPath='UnityLoader/UnityLoader.js'" "locals.outputPath='C\x3a/Test Folder/New Unity Project \x2838\x29/builds/Build/builds.loader.js'" "locals.minifyOutput=true" "COMPANY_NAME='DefaultCompany'" "PRODUCT_NAME='New Unity Project \x2838\x29'" "PRODUCT_VERSION='0.1'" "WIDTH=960" "HEIGHT=600" "SPLASH_SCREEN_STYLE='Dark'" "BACKGROUND_COLOR='\x23231F20'" "DATA_FILENAME='builds.data.gz'" "FRAMEWORK_FILENAME='builds.framework.js.gz'" "CODE_FILENAME='builds.wasm.gz'" "MEMORY_FILENAME=''" "SYMBOLS_FILENAME=''" "BACKGROUND_FILENAME=''" "USE_WASM=true" "USE_THREADS=false" "USE_WEBGL_1_0=true" "USE_WEBGL_2_0=true" "USE_DATA_CACHING=true" "DECOMPRESSION_FALLBACK=''" "TOTAL_MEMORY=16777216" "DEVELOPMENT_PLAYER=false" "UNITY_VERSION='2021.2.0a18'" "LOADER_FILENAME='builds.loader.js'"
##### ExitCode
1
##### Output
fs.js:640

return binding.open(pathModule._makeLong(path), stringToFlags(flags), mode);