Map crashes on Load

Development Programming & Scripting
1

Good Afternoon,

We ran into a bug preventing a map from loading in our project using 4.10.1. I have created a simple standalone project with the map that should make it quick for you to recreate the crash on your end and get it added to the bug list for a future permanent resolution. Let me know and I’ll shoot you the dropbox link.

Thanks.

See attached for the stack trace.link text

2

Hi ,

  • Does this occur in a clean, blank project with no additional content or is it limited to one project?
  • Can you post your crash logs here? They can be found at \Unreal Projects\PROJECTNAME\saved\logs\
  • What steps can I take to reproduce this on my end?
  • Is this project from 4.10 or did you convert it from a previous version of the engine?
3

Hi ,

  • Yes, this occurs in a clean blank project with only the map.
  • See attached.link text
  • Download a simplified project with just the map. The map is from one of my student’s projects, and it’s just the map in an empty project with no assets, so there shouldn’t be any copyright concerns sharing it here to help you get this resolved for them: https://www.dropbox.com/s/m81czyeniter1t6/Bug2.?dl=0
  • The map was created with a previous version of the engine, but was converted as later versions were released.
4

Does the map still load in the previous engine version? I am seeing a lot of Null reference errors in the logs, were there many changes made to the project just before updating? Try using fix up redirectors in the engine version this project was working in and then updating by creating a copy to 4.10. Ensure that there aren’t any NULL references for the map before updating to the new version. Does this fix the error in question?

5

This unfortunately presents a problem, as the project was converted in place due to its size. We also no longer have any previous version installed, as we have been focusing on development with the latest build released in the launcher. At this point, considering the map in question had a fraction of the time put into it as many of the other maps in the project, it’s probably less of a headache to recreate it. My hope was to at least get the bug that caused it entered into the system so no one else would face the same problem into the future. Thank you for your time on this .

6

I went ahead and added a bug report, UE-24762 into our system to be assessed by the development staff.

7

The problem seems to be that the LightComponent on a DirectionalLight actor has someone become invalid or null. I’m afraid I can’t think of any way that could happen, it could just be a corrupted file. If you are building the engine yourself, you could try changing the engine code in that function (ADirectionalLight::PostLoad) to check GetLightComponent() is non-null before accessing it, but you may find it crashes somewhere else. As you say, the best solution might be to roll back to an earlier version in revision control. Please do let us know if you see this again, or even better, if you have reproduction steps.