Engine crashes when building lighting (engine version 4.12.4)

hello so i been working on a few of my maps and i haven’t built any of the lighting since 4.12.3 so after adding more items to them and i go to build the lighting the engine crashes… it hasn’t done this since 4.12.3 so i thought i should report it

Update: so i found the error to be the swarm agent but restarting did not solve it, after reading the logs it says something about a incorrect line of code on the agent application on the main at line 133… here is the log

Can you please post the following:

  • Call Stack from the crash reporter window.
  • Epic and Machine ID’s
  • Include the Project log from Project Folder > Saved > Logs

Thank you!


ok could not get call stack as the reporter window does not open

i do not know where to find epic and machines id nor can i find any info about it

i have included log →

i could not upload it here due to size

Seeing that you’re using ShooterGame I tried to build the lighting on this level with production settings for the build and did not get a crash on my end.

Looking at the Log it looks like the Editor closed without bringing anything else up, like the Crash Reporter window, as you indicated.

If this is the case that the editor closed completely without anything else can you please follow the steps in this Wiki guide? A new, community-hosted Unreal Engine Wiki - Announcements - Epic Developer Community Forums

Typically when the editor crashes like this it’s due to an error within Windows that causes the program to crash. The information from the log above should help to identify the error code that Windows generates for the crash.

Also, is it only happening in this project or are you able to build lighting for other projects without issue? It may be a memory usage issue where Windows is running out of RAM. looking at the log I could see that have 16GB of RAM, of which 7GB was being used for ShooterGame, which leaves 9GB for Windows, other programs, and the light build to process which may not have been enough.

Let me know.

lol no that’s not the example shootergame i couldnt come up with a name at that time so i called it shootergame lol this project is built from scratch

at first i thought that i added too much items to the scene so i have deleted most of them to see if that was causing it but it wasnt…tho keep in mind the scene in the past has held 6000 individual objects and calculated the lighting just fine

i shall check out the wev

update: nothing is shown in the event viewer that has a connection to unreal… as i mentioned in the logs it seems to be the swarm agent… something about not connecting and something about a issue in its code

Retrieve the super verbose logs from Swarm Agent following instructions in this page.

Swarm should not cause the editor to crash since it’s a separate program that handles the building process.

You may also want to follow notes in this page to see if Swarm is using the right ports. If not, you’ll want to correct this on your machine since this is not an issue with UE4 or Swarm but your machine and the ports that are free.

ok so following the link Does UE4 / Swarm Require a "D" Drive? - Rendering - Epic Developer Community Forums
this was the same issue i was facing in terms of logs and all and managed to solve it by running it once with administrator then turning it off in properties and restarting computer (note that i had to turn it back off and restart because it would still give me an error)

ok so credit goes to tim for giving me the link. but if anyone is facing the same issue as me go into the directories and find the swarm agent, right click and run as administrator then after that go into the swarm agent exe properties and disable administrator and restart computer… this is how i fixed the issue i was facing

here is the link tim provided Does UE4 / Swarm Require a "D" Drive? - Rendering - Epic Developer Community Forums

thanks tim!!