For anyone who still has this issue, simply scale everything to 0.1 - 0.01 - those areas should make the GI render much faster since it takes these Units into consideration. Make those settings within the importer not the scene.

Confirmed it is still present in 5.2.3, Unity you guys have ruined my life, losing millions of dollers worth of productivity by now over the years. How do you feel being responsible for screwing thousands of developers with your poorly optimized/coded engine.

Now the core of its lighting claims is completely broken making it unusable entirely. Beast was the way to go.

Ive found the problem, go to the lighting tab. Then scroll all the way down to other settings. Then you will see a box that says auto, uncheck it.

KKOSTECKIMAY 12, 2015 10:41
NIGHTCODER99 have 100% right, it seems that Enlighten precompute (clustering) has a problem with big meshes, "BIG" means not in terms of vertices or faces but their scale.

Steps to reproduce:
You can freeze GI simply putting one plane on the scene (even Plane object from Unity) and scaling it 16 times (16,16,16). Now try to build GI lighting (even without baking textures - only realtime), job freezes at clustering.

Workaround:
Instead of using one plane 16x16 try to create more planes but smaller in dimensions, the problems solves immediately. For example 16 planes scaled twice time (2x2).

THANK YOU!!! That solved it for me. OMG so frustrating.
I was stucked for weeks and weeks here. Shame on Unity.

Such a bug.

Funny thing is, even if the light do not impact a large scale because it is somewhere totally else it get stucked.

KKOSTECKIMAY 12, 2015 10:41
NIGHTCODER99 have 100% right, it seems that Enlighten precompute (clustering) has a problem with big meshes, "BIG" means not in terms of vertices or faces but their scale.

Steps to reproduce:
You can freeze GI simply putting one plane on the scene (even Plane object from Unity) and scaling it 16 times (16,16,16). Now try to build GI lighting (even without baking textures - only realtime), job freezes at clustering.

Workaround:
Instead of using one plane 16x16 try to create more planes but smaller in dimensions, the problems solves immediately. For example 16 planes scaled twice time (2x2).

THANK YOU!!! That solved it for me. OMG so frustrating.
I was stucked for weeks and weeks here. Shame on Unity.

Such a bug.

Funny thing is, even if the light do not impact a large scale because it is somewhere totally else it get stucked.

It is a scaling problem. I was exploring fluvio and wound up using one it's settings to accidentally scale my entire project several times. Once I fixed this (by returning everything to a normal scale as compared to my static objects) the lighting jobs finished as normal.

I was having this problem and was frustrated by the lack of a solution on here, or in other forums.

I kept on tweaking things however, and having been stuck on 7/11 with 66 processes to run for about 4 hours, i changed some settings that seem to have kicked it into life.

I am a newbie using 5.2.1f1,and it may have been a coincidence, but personally I dont believe in them.

So, my scene is outside, with a high sun directional type light source. All I have done is taken the intensity down to 0.4 with soft shadows and medium resolution.

Hope it works for some of you, if it doesnt, then its back to Unity to sort out

I'm stuck on 5.1.2f1 for school, and this is a highly irritating issue. I seriously have to disable Precomputed Realtime GI and Baked GI for my relatively small level to even build. Otherwise it consistently grinds to a halt at 7\11 Light Transport.

Make sure the "Precomputed Realtime GI" option is unchecked if you don't need it. Baking lightmap for large scenes (outdoor scenes for example) with this option checked will take very long time.
It solves the issue in our project.

5.2.2 seems to be as buggy as 5.2.1. As a matter of fact, Unity has been plagued with unprofessional regression errors ever since 5.0 was released.

Do something about it, Unity. You're about to start losing customers if you don't.