Problem building WebGL

I recently began to have problems trying to build WebGL version of my projects, I used to be able to build into WebGL before without problems.
Nothing has changed except for Unity version, I upgraded to 5.1.2f1.

Build paths are the same where I used to succesfully build WebGL version of projects.

Here is the error message
Failed running “E:\Program Files\Unity\Editor\Data\PlaybackEngines\webglsupport/BuildTools/Emscripten_Win/python/2.7.5.3_64bit/python.exe” “E:\Program Files\Unity\Editor\Data\PlaybackEngines\webglsupport/BuildTools/Emscripten/emcc” @“D:/Eduardo/Game Development/GIT/Homelessness_GIT/Prototipos/PrototipoHomelesness/Assets/…/Temp/emcc_arguments.resp”

stdout:
stderr:
WARNING root: emcc: link command line is very long, even with response file – use paths with no spaces

Any ideas to solve this issue?

We fixed a similar issue a few weeks ago, which was caused by the length of the project path. Could you please try to temporarily move the project folder to the drive root and rebuild?