Hello,
Did you make sure that you cleared the cache of your browser to load the latest version of the workshop code? Files transferred to the render server are different (much smaller) than before. If the old version of the workshop code is used, file format will be incorrect and render will fail.

I tried to clear the cache (I'm on Chrome) and that appeared to work fine but the rendering had the same outcome. Do I need to go further and clear cookies as well?

No, no need to clear the cookies.
Can you render anything at all? Like a 1 brick model? Just to understand if the issue is with this particular model.

I could find the blend file building errors. Only 2 types are occurring:

• Obviously the first and main one is when people don't have the latest workshop version.
• The second one comes from lamps and mainly the point lamp color value.
  I guess yours comes from number 2. I cannot reproduce it right now. I'll keep trying. But if you could isolate the lamp(s) that makes it fail and give me the hex value, that would be awesome.

I just tried testing a simple render of a centered 2x2 brick and a black background with HDRI lighting. Everything set to basic settings. I did not use credits. It took about 9 - 10 minutes to get through the queue and another minute to render but it worked fine.

I added custom lights in and they all work and the also show up in preview. I think the issue is my lamps are from the previous version. I'll switch them out and then try again.

Edit: Yep, that was it. I replaced some area lights and its working now. Thank you!

Edit #2: Preview is working but it still failed to render after a minute. I'll check the light values.

Could you please retry with a model that is failing. I added stuff in the server code to debug it.

So, it is actually another issue. Your file is built properly, however it crashes at render time. I managed to retrieve the Blender file. As soon as I launch a render with Blender 2.80 (macOs or Ubuntu) it crashes... Looks like it is a bug from the beta... I will check to see what Cycles doesn't like.

So after six trials with the three random shades of area lamp used in various places in the scene:

E8E0D3 1 1 0 1 0 0

DFD7CC 1 0 1 0 1 0

CAC3B6 0 1 1 0 0 1

             0   0   0   0   0   0

Analysis: Either I somehow managed to pick three hex codes that didn't work or something else is the issue. I would guess the area light type would be the problem so I continued:

A control test with just HDRI also failed so maybe the issue is with my model?

Another control test, this time with a different, previously successful scene and only HDRI rendered perfectly. (no credits were used -- I'm going through everything I can here)

Same model as ^ but with only one default area light and no HDRI. Still no credits: worked (and Actually made a really cool image. I may use that later)

Same as ^ but with credits this time: Worked.

Then, I simply tried to re-render that a previous complex scene to see if that changed anything. I did not change over the lights to the new system so I'm not surprised it didn't work.

I tried a model that I made before the system change but I added in a bunch of lights (sun and area) and it worked.

The only thing I hadn't tried changing yet was the FoV value. I changed it to 40 and it still worked.

Conclusion: I have no idea. It seems to be an issue with the scene, rather than with the lighting. Would there be any parts that could cause issues? It isn't flexible parts either because some of the scenes that worked had those in them.

Edit: Haha sorry, I didn't realize you had checked it before me.

I found the issue but I need to investigate some more. I managed to isolate the parts that crashes Blender 2.80: 3069d230.
I have no idea why for now.

I may actually be able to solve the lamp issue with your help too. You model "Hab Interior 2" could not be built because of a lamp issue. Could you check the hex color values from the lamps in this model.

I found out the type of parts crashing Blender: Transparent decorated parts with a metalness map.

Yep, that sure was the issue. I hid those parts and it worked. For the hab interior scene, the problem appears to be that the lamps (I was using the old ones) are not properly supported and that the information on color and length do not carry over. If I go to edit one, the object edit area is different with the sliders in different places and the color picker missing. Under strength, they all say "NaN"

Thank you for that. I will check the lamp issue.
I am trying to find the bug in Cycles to report it to Blender.

Transparent part with metalness maps shall now work. Solution is not perfect and hopefully this problem will be fixed in the released version of Blender 2.80. At least now, it won't make the render fail.

I found the bug for the old lamps properties. However it will be really complicated to solve. Not too sure what to do. It is a bit of a mess!
Maybe sacrifice old models. Lamps will simply not work in them. What are you thoughts?

Well the models themselves have been working for me, It's only the old lighting that is the issue it seems. My idea is actually based on something from Blender: There is a type of clone command that remains active after cloning such that any changes to one of the objects is also changed on the others. If that feature were available in here, it would make replacing a ton of lamps much easier as you would only have to edit the properties of one of them. If that were combined with some sort of find-and-replace function, one could replace all of the old lamps with the new lamps and then only edit one of the new lamps to change them all. I have no coding experience so I don't know how hard that would be though.

Basically though, the old models are fine, people just have to replace the lights. I don't personally think it is that big of an issue, more of just an inconvenience.

Yes for sure. We may have to live with it for now though.

I keep thinking about it. I hate not fixing bugs I am aware of. I’ll find a solution tomorrow and tidy up this part of the code.

All fixed!

Excellent! Thank you so much, you truly are the master