Error: Content is missing from cook. Source package referenced an object in target package but the object was stripped out of the target package when saved. Source package: /Game/Maps/MapName/_Generated_/285ZFF1S2X8K1FMHSHB022CXO Target package: /Game/Scenarios/Dynamic_BP Referenced object: /Game/Scenarios/Dynamic_BP.Dynamic_BP_C:InstancedStaticMesh10_GEN_VARIABLEI’m intermittently getting this error during cooking on a bunch of actors placed on a WorldPartition map. They are all the same class. It’s complaining about all it’s InstancedStaticMeshes.
I don’t know how to diagnose this and it’s inconsistently happening, making it a pain to track down.
Wanted to add here that we are suffering the exact same problem:
Started several weeks ago.
We were on UE 5.5.3 at that time. Note that the issue did not start at the same time we switched to UE 5.5.3. Everything was cooking fine for several months actually (we switched to 5.5.3 on the 7th of February 2025, and we started getting those cooking errors at most a month ago, end of May).
The source packages are always _Generated_ packages from some level (I guess those are the individual levels that world partitioning stencils out from the spatial/data layer information?).
The target is always a child blueprint in a blueprint hierarchy, and the target object is always a static mesh component that is inherited from the parent blueprint. It seems like all instances of the blueprint in that world partition map are affected.
Rerunning the same build on the same machine can result in the same error, an error with a different blueprint instance in a different level, or the error going away. It’s completely random.
Here’s the errors from one of our cooks - I’ve been keeping a file with all of them as they happen, to see if I can determine some commonality:
01:54:27 LogCook: Error: Content is missing from cook. Source package referenced an object in target package but the object was stripped out of the target package when saved. 01:54:27 Source package: /Game/GG/Levels/Atlantis/WP_Atlantis/_Generated_/47WZYRHL2HSDOVKRK0OC4RPQZ 01:54:27 Target package: /Game/GG/Props/SimpleInteractables/BP_Candle_01_Interactable 01:54:27 Referenced object: /Game/GG/Props/SimpleInteractables/BP_Candle_01_Interactable.BP_Candle_01_Interactable_C:SM_CandleFlame_Base_GEN_VARIABLE 01:54:27 LogCook: Error: Content is missing from cook. Source package referenced an object in target package but the object was stripped out of the target package when saved. 01:54:27 Source package: /Game/GG/Levels/Atlantis/WP_Atlantis/_Generated_/2U721CECHXV8204I5KMCFQIUK 01:54:27 Target package: /Game/GG/Props/SimpleInteractables/BP_Candle_01_Interactable 01:54:27 Referenced object: /Game/GG/Props/SimpleInteractables/BP_Candle_01_Interactable.BP_Candle_01_Interactable_C:SM_CandleFlame_Base_GEN_VARIABLE 01:54:27 LogCook: Error: Content is missing from cook. Source package referenced an object in target package but the object was stripped out of the target package when saved. 01:54:27 Source package: /Game/GG/Levels/Atlantis/WP_Atlantis/_Generated_/E3TXZR524IV1B0V80WVQCJCSA 01:54:27 Target package: /Game/GG/Props/SimpleInteractables/BP_Candle_01_Interactable 01:54:27 Referenced object: /Game/GG/Props/SimpleInteractables/BP_Candle_01_Interactable.BP_Candle_01_Interactable_C:SM_CandleFlame_Base_GEN_VARIABLE 01:54:27 LogCook: Error: Content is missing from cook. Source package referenced an object in target package but the object was stripped out of the target package when saved. 01:54:27 Source package: /Game/GG/Levels/Atlantis/WP_Atlantis/_Generated_/57ZK6UUTFXGO99TDCCH8PAH7A 01:54:27 Target package: /Game/GG/Props/SimpleInteractables/BP_Candle_01_Interactable 01:54:27 Referenced object: /Game/GG/Props/SimpleInteractables/BP_Candle_01_Interactable.BP_Candle_01_Interactable_C:SM_CandleFlame_Base_GEN_VARIABLE 01:54:27 LogCook: Error: Content is missing from cook. Source package referenced an object in target package but the object was stripped out of the target package when saved. 01:54:27 Source package: /Game/GG/Levels/Atlantis/WP_Atlantis/_Generated_/BXZU2EL20OFDES3RXVQY3DYSY 01:54:27 Target package: /Game/GG/Props/SimpleInteractables/BP_Candle_01_Interactable 01:54:27 Referenced object: /Game/GG/Props/SimpleInteractables/BP_Candle_01_Interactable.BP_Candle_01_Interactable_C:SM_CandleFlame_Base_GEN_VARIABLE 01:54:27 LogCook: Error: Content is missing from cook. Source package referenced an object in target package but the object was stripped out of the target package when saved. 01:54:27 Source package: /Game/GG/Levels/Atlantis/WP_Atlantis/_Generated_/D22G271XT5ZSB7OCIH8BHKTFI 01:54:27 Target package: /Game/GG/Props/SimpleInteractables/BP_Candle_01_Interactable 01:54:27 Referenced object: /Game/GG/Props/SimpleInteractables/BP_Candle_01_Interactable.BP_Candle_01_Interactable_C:SM_CandleFlame_Base_GEN_VARIABLE 01:54:27 LogCook: Error: Content is missing from cook. Source package referenced an object in target package but the object was stripped out of the target package when saved. 01:54:27 Source package: /Game/GG/Levels/Atlantis/WP_Atlantis/_Generated_/52R1PTMC8JOKH9MK73KLWC2BA 01:54:27 Target package: /Game/GG/Props/SimpleInteractables/BP_Candle_01_Interactable 01:54:27 Referenced object: /Game/GG/Props/SimpleInteractables/BP_Candle_01_Interactable.BP_Candle_01_Interactable_C:SM_CandleFlame_Base_GEN_VARIABLE 01:54:27 LogCook: Error: Content is missing from cook. Source package referenced an object in target package but the object was stripped out of the target package when saved. 01:54:27 Source package: /Game/GG/Levels/Atlantis/WP_Atlantis/_Generated_/347R57QY1BGV1U960XYA0MS2M 01:54:27 Target package: /Game/GG/Props/SimpleInteractables/BP_Candle_01_Interactable 01:54:27 Referenced object: /Game/GG/Props/SimpleInteractables/BP_Candle_01_Interactable.BP_Candle_01_Interactable_C:SM_CandleFlame_Base_GEN_VARIABLE 01:54:27 LogCook: Error: Content is missing from cook. Source package referenced an object in target package but the object was stripped out of the target package when saved. 01:54:27 Source package: /Game/GG/Levels/Atlantis/WP_Atlantis/_Generated_/44NYTS4KL40H7WGPTSAS61KCP 01:54:27 Target package: /Game/GG/Props/SimpleInteractables/BP_Candle_01_Interactable 01:54:27 Referenced object: /Game/GG/Props/SimpleInteractables/BP_Candle_01_Interactable.BP_Candle_01_Interactable_C:SM_CandleFlame_Base_GEN_VARIABLE 01:54:27 LogCook: Error: Content is missing from cook. Source package referenced an object in target package but the object was stripped out of the target package when saved. 01:54:27 Source package: /Game/GG/Levels/Atlantis/WP_Atlantis/_Generated_/C6YUBCUAV8ZB9I346IDX4O4SB 01:54:27 Target package: /Game/GG/Props/SimpleInteractables/BP_Candle_01_Interactable 01:54:27 Referenced object: /Game/GG/Props/SimpleInteractables/BP_Candle_01_Interactable.BP_Candle_01_Interactable_C:SM_CandleFlame_Base_GEN_VARIABLE 01:54:27 LogCook: Error: Content is missing from cook. Source package referenced an object in target package but the object was stripped out of the target package when saved. 01:54:27 Source package: /Game/GG/Levels/Atlantis/WP_Atlantis/_Generated_/0CTBJGQ06C8L5TX923UN8EQO9 01:54:27 Target package: /Game/GG/Props/SimpleInteractables/BP_Candle_01_Interactable 01:54:27 Referenced object: /Game/GG/Props/SimpleInteractables/BP_Candle_01_Interactable.BP_Candle_01_Interactable_C:SM_CandleFlame_Base_GEN_VARIABLE 01:54:27 LogCook: Error: Content is missing from cook. Source package referenced an object in target package but the object was stripped out of the target package when saved. 01:54:27 Source package: /Game/GG/Levels/Atlantis/WP_Atlantis/_Generated_/98EXQSL5V4XWZH3F9C9N9QTVG 01:54:27 Target package: /Game/GG/Props/SimpleInteractables/BP_Candle_01_Interactable 01:54:27 Referenced object: /Game/GG/Props/SimpleInteractables/BP_Candle_01_Interactable.BP_Candle_01_Interactable_C:SM_CandleFlame_Base_GEN_VARIABLE 01:54:27 LogCook: Error: Content is missing from cook. Source package referenced an object in target package but the object was stripped out of the target package when saved. 01:54:27 Source package: /Game/GG/Levels/Atlantis/WP_Atlantis/_Generated_/A042WMJO7C2QK27ZGCMWDCSZJ 01:54:27 Target package: /Game/GG/Props/SimpleInteractables/BP_Candle_01_Interactable 01:54:27 Referenced object: /Game/GG/Props/SimpleInteractables/BP_Candle_01_Interactable.BP_Candle_01_Interactable_C:SM_CandleFlame_Base_GEN_VARIABLE 01:54:27 LogCook: Error: Content is missing from cook. Source package referenced an object in target package but the object was stripped out of the target package when saved. 01:54:27 Source package: /Game/GG/Levels/Atlantis/WP_Atlantis/_Generated_/0D25UI7FYTR31RSDVP8GT2SM0 01:54:27 Target package: /Game/GG/Props/SimpleInteractables/BP_Candle_01_Interactable 01:54:27 Referenced object: /Game/GG/Props/SimpleInteractables/BP_Candle_01_Interactable.BP_Candle_01_Interactable_C:SM_CandleFlame_Base_GEN_VARIABLE* I’ve so far only seen this error happen to UStaticMeshComponent as well as our own UPL_StaticMeshComponent derived from it (it’s super simple and just adds a gameplay tag container for convenience).
The components are simply added in the blueprint editor, not added as a component from C++ or anything else.
There are no special properties on those components. If you make a new actor blueprint from scratch, and add a static mesh component in the blueprint editor, that’s exactly what this is.
I’ve checked several of the affected blueprints, and there was never any reparenting or other ‘finicky’ operations done to them. For example, the history of the BP_Candle_01_Interactable above is:
It was initially simply a static mesh that was imported into the editor.
At some point someone needed to add a flame, so it got turned into a BP_Candle_01
Then later we wanted to make it interactable, so someone created a child blueprint of it.
I have the feeling that this isn’t much to go on, sadly.
I’m currently in the process of integrating UE 5.6.0, and I’ve been getting the same cooking errors with that version as well.
Hi Daniel, did you open another thread? I have heard 2 reports so far, your report being the 3rd, of Content is missing from cook for _GET_VARIABLE objects in 5.6. We haven’t been able to diagnose any of them yet; the licensees with the problem have worked around the issue by removing the content in those other two cases. I would really like to get to the bottom of it, but I think it will take some deep investigation, with multiple rounds of instrumentation and experimentation.
None of the changes that fixed the issue that we put into 5.6 rely on resaving the content; they fixed some handling of out of date compiled data in blueprints so that the resave was not necessary.
Please start a new ticket for your case and we’ll do whatever back and forth is necessary on that ticket.
Put an [Content removed] but FYI I’m planning on sending it to the blueprint team who have better expertise on the issue and have also been working on a few of these issues in 5.6 already.
thanks for letting us know, glad to hear these seem to work for you!
Feel free to update us here in case you see any further problems.
[mention removed] If you can it might be worth trying out these CLs on your end, too.
If they doesn’t help in your case, may I ask you to create a new question with your info (or link to your post here), so that we can investigate this separately?
Please be aware that Epic will be on Summer break for the next 2 weeks, so our support in that time will be very limited, it’s likely we’ll only get back to you after the break.
For a while, we were diligently resaving every asset that would pop up in one of those cooking errors, thinking that it might help. The cargo cult was strong with us.
But yesterday I noticed that one of the already resaved assets was again in one of the cooking errors. So just like you said, resaving doesn’t help.
New post created here: [Cooking Error "Content is missing from cook. Source package referenced an object in target package but the object was stripped out of the target package when [Content removed]