WebGL will not build, gets stuck at IL2CPP or asm.js, even with fresh Unity install and empty scene.

Even with a scene containing no assets or only the camera and primitives, WebGL gets absolutely stuck during build. I have built to WebGL in the past, pretty quickly even with my own assets. This used to happen to me, in older versions - I found the solution of changing some lighting settings (rather, turning all the lighting features off that I could) and then it wouldn't always look as nice, but it looked good enough for WebGL and I could actually build it. now though, since 5.6 it seems, the lighting window is different, and Google doesn't seem to have any answers...If anyone has any experience with the problem or has a solution please let me know, thanks in advance.