The engine may touch freed memory at D3DX12Residency::Internal::RemoveEntryList.
The memory release operation that is causing the problem is in  FD3D12DynamicHeapAllocator::AllocUploadResource().
If there are over 128 items in DeferredDeletionQueue, the allocator will release these immediately.
 if (Adapter->GetDeferredDeletionQueue().QueueSize() > 128)
 {
     Adapter->GetDeferredDeletionQueue().ReleaseResources(true, false);
     Allocator.CleanUpAllocations();
 }
The licensee says that removing this code or disabling D3D12.ResidencyManagement can avoid this error.
It may be reproduced by traveling from a level containing many assets.
[Inline Frame] Game.exe!D3DX12Residency::Internal::RemoveEntryList(_LIST_ENTRY * pEntry) Line 368    C++
 [Inline Frame] Game.exe!D3DX12Residency::Internal::LRUCache::ObjectReferenced(D3DX12Residency::ManagedObject * pObject) Line 557    C++
 Game.exe!D3DX12Residency::Internal::ResidencyManagerInternal::ProcessPagingWork(D3DX12Residency::Internal::ResidencyManagerInternal::AsyncWorkload * pWork) Line 1095    C++
 Game.exe!D3DX12Residency::Internal::ResidencyManagerInternal::AsyncThreadStart(void * pData) Line 1021    C++
 [External Code]
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-95275 in the post.
| 4 | 
| Component | UE - Rendering Architecture - RHI | 
|---|---|
| Affects Versions | 4.25 | 
| Target Fix | 4.26 | 
| Created | Jul 13, 2020 | 
|---|---|
| Resolved | Oct 23, 2020 | 
| Updated | Nov 20, 2020 |