Can't build lights and objects in UE 4.12.5

Development Rendering
, , ,
1

I’ve just converted my project from 4.10 to 4.12.5 and after fixing some compiler errors due to compatibility, I know can’t get the same lighting in my level as I used to have in 4.10

This is how my level looks like in 4.10
![alt text][1]

And this is how it looks in 4.12
![alt text][2]

Bulding everything gives me error I never had in 4.10:

![alt text][3]

In case you’re asking: yes, the objects in the level actually have a Static mesh property which is not NULL

I followed this guide: A new, community-hosted Unreal Engine Wiki - Announcements - Unreal Engine Forums

Rebuilt the Lightmass project and still no luck!

2

Hi gedamial,

Looking at your screenshots the second screenshot does not have your Engine Scalability set to EPIC.

For the NULL actors, click on the ones in the warnings and to show the actor in the scene and make sure that they have an assigned Static Mesh. If they do and they are still the causing the issue try to unassign the static mesh and re-assign the static mesh.

I guess since you linked to the section of the Wiki I wrote for Swarm Failed to Kick Off and that you are using a source build, that you’re also having issues there?

  • If so, please make sure that you’ve properly built Lightmass.
  • Test in a Default new level to see if Swarm Builds.
  • Try a binary version of the editor to see if Lighting builds. This can rule out if something else is potentially blocking Swarm from starting. If it does build there is something you need to correct in your Source Build to get Lightmass properly compiled to work with Swarm.

Thank you!

Tim

3

Hi.
I tried re-assigning the mesh to my actors, but I still get those warnings.

4

I’m sorry, but the issue is not solved. I keep getting those annoying warnings.

5

The suggestions from the wiki I have should help you resolve the issue. If not, then there is something that is still happening but you will need to investigate.

If you can reliably reproduce in a blank project or a new level with your project please post the detailed steps here to reproduce the issue and I’ll give it a test. If you’re only experiencing this issue in this current project I cannot help other than the suggestions I’ve given.

You have also neglected to mention if you’ve tried any other the other suggestions above. Please let me know the following before we proceed further.

  • Does this happen only in your project? If so, is it only in this level?
  • Does this happen in a new project?
  • Are you using a source build of the engine or the binary version from the launcher? If you’re using a source build, try rebuilding lightmass.
  • Have you tried investigating your current level where you cannot build lighting by deleting objects one by one and rebuilding each time to see if it’s a specific actor that’s causing the issue?
  • Have you tried any previous or newer versions of the engine like 4.11 or 4.13? If so, does the issue happen there?
  • Have you tried deleting all the folders in your project with exception of the Uproject file and the Content folder? Then re-open the project and rebuild lighting. This will wipe any intermediate or previous info that is possibly corrupt.
  • Try deleting the DerivedDataCache and see if that helps. Will be located in C:\Users[Computer Name]\AppData\Local\UnrealEngine