WebGl build failing with IOError: [Errno 28] No space left on device

I am a newbie trying to build the “Standard Assets Example Project” on Windows 10 systems with Unity 5.2. The build target is WebGL (Preview). It fails while running python.exe. What is wrong and what can I do to fix it? I have space on my disk and the folder has read write permissions. See error description below

Failed running “C:\Program Files\Unity\Editor\Data\PlaybackEngines\webglsupport/BuildTools/Emscripten_Win/python/2.7.5.3_64bit/python.exe” “C:\Program Files\Unity\Editor\Data\PlaybackEngines\webglsupport/BuildTools/Emscripten/tools/file_packager.py” “bin.data” --no-heap-copy --js-output=“fileloader.js” --preload “level0” “level1” “level10” “level2” “level3” “level4” “level5” “level6” “level7” “level8” “level9” “mainData” “methods_pointedto_by_uievents.xml” “sharedassets0.assets” “sharedassets1.assets” “sharedassets1.resource” “sharedassets10.assets” “sharedassets11.assets” “sharedassets2.assets” “sharedassets3.assets” “sharedassets3.resource” “sharedassets4.assets” “sharedassets5.assets” “sharedassets5.resource” “sharedassets6.assets” “sharedassets6.resource” “sharedassets7.assets” “sharedassets8.assets” “sharedassets9.assets” “Il2CppData/” “Resources/unity_default_resources” “Resources/unity_builtin_extra”

stdout: stderr: Traceback (most recent call last): File “C:\Program Files\Unity\Editor\Data\PlaybackEngines\webglsupport/BuildTools/Emscripten/tools/file_packager.py”, line 390, in data.write(curr) IOError: [Errno 28] No space left on device

Have you tried with Unity 5.2.2 ?