Sub-Levels' BP Actors being randomly set to 0,0,0 location

Hi all,
today i came across with an old 4.8 bug already reported here: .html

My project is a BP only project in 4.11.2, no plugin installed
I have a persistent level and a lot of sub-levels and of course i use manual streaming level (i do not use streaming volumes)

Today starting up my project i noticed that almost 90% of the BP Actors placed in several sub-levels were gone.
Remembering the old bug from versione 4.8 i checked the 0,0,0 location finding all the BPs there.

To give even more details, during these days i’m working with sub-levels, sorting all the actors from persistent level to the corresponding sub-levels.
A few times move actors from persistent to a sub-level caused an engine crash, don’t know if it has something to do with the bug.

Unfortunately i’m not able to reproduce this bug in a clean blank project because it is completely random and i have no idea about what triggers it.

Thanks for any support/help

Hey FraZack,

I’ve spent some time testing this in a clean project. Basically I set up 4 levels to stream in to my persistent level, and then set up a looping custom event to randomly load and unload the levels every couple of seconds to see if I could get my actors to move to 0,0,0. Unfortunately, I haven’t been able to reproduce it at this time.

Could you provide any more details regarding your setup that may be helpful? If you recreate a simplified version of your setup in a clean project you’re not seeing the repro either, correct?

Hi Sean,
thanks for the quick reply!

I’ve uploaded this test enviroment project which shows how the level streaming is managed in our project.

I commented all possible BP sections to give more details on how it works.
Anyway, me and my team are working with this project for at least 8 months till now and this issue appeared only by today, this makes me think that the core of the problem is not in how the streaming is manually handled (this also because we came across with this problem even during 4.8 release period and at that time we were using only basic Streaming Volumes to manage sub-levels)

During the day the bug happened another couple of time:

  • In the first case it happened after a build and saving the sub-levels
  • In the second one instead it was triggered after enabling the visibility of all layers at once (as shown in the screenshot i’ve attached)

As i said it seems completely random :confused:

Just to be very specific the issue seem to be limited to Blueprint Class Actors only.
Static Mesh Actors, Emitters, Point Lights etc. instead are not affected by this bug.

Even more details:
the map total actor count is around 10000, and the average sub-level actors count is around 200-300.

Hey FraZack,

After spending some time attempting to reproduce the issue, I’ve been unable to get it to occur in a clean project.

Unfortunately, without a repro case internally, we are unable to take any further action regarding this issue.

However, if you are able to discover any further information that could be useful to us in reproducing the issue, feel free to leave a comment to reopen the thread and I’ll be glad to investigate.

Have a great day

I am also having this issue in 4.15.

Hey there. I’ve had this issue as well. It’s only happened to me once and I haven’t been able to reproduce it, but basically everything in one of my sub levels just disappeared. After trying to figure out what happened it just all ended up at position 0 0 0. It was a pretty significant level, too. Fortunately I had a recent backup I could roll back to.

Since it happened awhile ago I’m not exactly sure what I was doing, but due to the nature of the development phase I’m in it involves lots of BSP brushes and undo/redo in combination with meshes. At the point where it just all disappeared, I wasn’t even working near that sublevel. When I finally noticed it, undoing everything didn’t go back far enough to fix it. I don’t think I was at the limit for undos yet between when it happened and when I noticed it.

I thought maybe it was an error on my part (like maybe accidentally selecting everything and somehow hitting a hotkey that reset location) I didn’t really bother reporting it. But knowing other people have the issue, I’m glad I’m not alone in coming across this.

Hey MetricZero,

Thanks for the update. Could you attempt to reproduce the issue in a clean project and provide me with a detailed list of repro steps? I’ve attempted to reproduce this issue several times in the past, but unfortunately I’ve been unsuccessful thus far.

Had this issue multiple times today. 4.26.

Actors keep moving to location 0 when loading up a sublevel or the project. It appears to only be happening with static mesh items.

I have the same problem. Why is it happening?

I also experienced this issue in 5.1. But very rarely. I am also working with sub-levels. I am moving objects from 1 sublevel to another. It was one blueprint type, and its child classes. I dont change the position of these blueprints by code or anything

I’ve also been having this issue on 5.1.1 and it is literally driving me insane. I cant figure out the cause apart from the fact that anything inheriting from another blueprint class seems to move to 0,0,0 and set itself to Movable (when it should be Static like its parent class)…