# Level saving bug, Graph is linked to external private object GEN\_VARIABLE.PhysicsSerializer (PhysicsSerializer) **URL:** \ **Category:** World Creation\ **Tags:** serialization, unreal-engine, bug-report, editor, question, Blueprint\ **Created:** [February 20, 2017, 2:42pm UTC](https://forums.unrealengine.com/t/level-saving-bug-graph-is-linked-to-external-private-object-gen-variable-physicsserializer-physicsserializer/385543 "2017-02-20T14:42:50Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![anonymous\_user\_4a7fa2b3](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_4a7fa2b3](https://forums.unrealengine.com/u/anonymous_user_4a7fa2b3)\ **Post date:** [February 20, 2017, 2:42pm UTC](https://forums.unrealengine.com/t/level-saving-bug-graph-is-linked-to-external-private-object-gen-variable-physicsserializer-physicsserializer/385543/1 "2017-02-20T14:42:50Z")
Steps to recreate: 1. create new project with starter content 2. create new BP\_CustomInstancer blueprint, that is inherited from InstancedStaticMesh component 3. create BP\_CustomActor actor blueprint, and add BP\_CustomInstancer to it 4. Add BP\_CustomActor to level, and save. 5. Set default StaticMesh for BP\_CustomInstancer inside BP\_CustomActor blueprint, apply and save. 6. Now set default StaticMesh just for BP\_CustomInstancer alone, hit apply and save. Now, when saving level with BP\_CustomInstancer in it, i get the following error ![127026-ue4_save_error.png](https://d3kjluh73b9h9o.cloudfront.net/original/4X/f/1/c/f1c056ee5420f19e27ce79e43d241cdc74b93737.png) After hitting yes, i get the following error: Warning Can’t save …/…/…/…/…/…/Workspace/MyProject/Content/StarterContent/Maps/Minimal\_Default.umap: Graph is linked to external private object PhysicsSerializer /Game/BP\_CustomActor.BP\_CustomActor\_C:BP\_CustomInstancer\_GEN\_VARIABLE.PhysicsSerializer (PhysicsSerializer) File-\>Refresh nodes doesn’t help, the only way i can save level after this is to remove all instances of BP\_CustomActor from it. This is a showstopper for me =/ The bug also exists in 4.13.2 ---
**Author:** ![anonymous\_user\_e729f54e](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_e729f54e](https://forums.unrealengine.com/u/anonymous_user_e729f54e)\ **Post date:** [February 20, 2017, 3:46pm UTC](https://forums.unrealengine.com/t/level-saving-bug-graph-is-linked-to-external-private-object-gen-variable-physicsserializer-physicsserializer/385543/2 "2017-02-20T15:46:31Z")
Hello Dmitriy\_Filipchuk, I was able to reproduce this issue on our end. I have written up a report and I have submitted it to the developers for further consideration. I have also provided a link to the public tracker. Please feel free to use the link provided for future updates. Link: [Unreal Engine Issues and Bug Tracker (UE-42144)](https://issues.unrealengine.com/issue/UE-42144) Make it a great day ---
**Author:** ![anonymous\_user\_4a7fa2b3](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_4a7fa2b3](https://forums.unrealengine.com/u/anonymous_user_4a7fa2b3)\ **Post date:** [February 20, 2017, 4:14pm UTC](https://forums.unrealengine.com/t/level-saving-bug-graph-is-linked-to-external-private-object-gen-variable-physicsserializer-physicsserializer/385543/3 "2017-02-20T16:14:32Z")
Hi, thanks. I think you specified engine version incorrectly, this bug exists at least from 4.13 onward, up to latest 4.15.0 ---
**Author:** ![Sn\_a\_ke](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Sn\_a\_ke](https://forums.unrealengine.com/u/Sn_a_ke)\ **Post date:** [May 27, 2017, 9:09am UTC](https://forums.unrealengine.com/t/level-saving-bug-graph-is-linked-to-external-private-object-gen-variable-physicsserializer-physicsserializer/385543/4 "2017-05-27T09:09:09Z")
In 4.16 the same error