Unreal Engine Issues
Unreal Engine Issues
Blueprints: ComponentClass override causes crash on loading maps with instances saved with base class
UE - Framework - Blueprint - May 1, 2026Context In actor blueprints, you can change an inherited component’s class in the editor by selecting it in a child blueprint and changing its Component Class in the Details panel. Problem When o ...
Wrong calculation of "MaxAllocatedCountEstimate" inside FNiagaraRendererRibbons::GenerateDynamicData()
UE - Niagara - Mar 20, 2026Starting with UE 5.4, function FNiagaraRendererRibbons::GenerateDynamicData() from file [NiagaraRendererRibbons.cpp] attempts to calculate DynamicData->MaxAllocatedCountEstimate as such: DynamicDat ...
LevelStreamingPersistence: Crash when streaming in destroyed map actor with persisted properties
UE - World Creation - Worldbuilding Tools - Mar 6, 2026Context The LevelStreamingPersistence plugin can be used to remember and restore properties on actors and components that are part of a streamed level. Saved property values are restored when a lev ...
LevelStreamingPersistence: BP added components don't persist properties in PIE until map actor resave
UE - World Creation - Worldbuilding Tools - Mar 6, 2026Context The LevelStreamingPersistence plugin can be used to remember and restore properties on actors, components and other objects that are part of a streamed level. Persisted properties are resto ...
LevelStreamingPersistence: BP variables that aren't Instance Editable get reset
UE - World Creation - Worldbuilding Tools - Mar 6, 2026Context The LevelStreamingPersistence plugin can be used to remember and restore properties on actors and components that are part of a streamed level. Blueprint variables can be marked as instan ...
Directly opening a modified map asset of a streaming sublevel does not always force it to be reloaded (inconsistent with other map open behaviors)
UE - World Creation - Worldbuilding Tools - Feb 10, 2026When the level currently being edited has unsaved changes and the user opens a new one, the Editor asks if the changes should be saved. If the user answers negatively, the level asset is reverted to ...
Texture streaming uses ISM component bounds instead of closest ISM instance
UE - Rendering - Architecture - Jan 22, 2026When regular texture streaming is used (not virtual textures), the largest mips are always loaded for ISM mesh textures whenever the camera is inside the bounds of the ISM even if the instances are ...
[Enhanced Input] The action instance data is incorrectly reset when you call "Add mapping context" on the same mapping multiple times
UE - Gameplay - Input - Jan 16, 2026This is somewhat related to [Link Removed] Closed and was brought up by a [Link Removed] Setting the CVar input.bRespectIM ...
Paper2D: Editor hangs when assigning Sprite Atlas Group to Sprite
UE - Gameplay - Paper2D - Dec 16, 2025In UE 5.3 and later, assigning a Sprite Atlas Group to a UPaperSprite asset can cause the editor to hang and eventually crash. This behavior has been reproduced in 5.3, 5.6, and a recent UE5-main so ...
Unreal Engine Fails to Launch with Vulkan SM6 RHI and RenderDoc Auto-Attach Enabled
UE - Rendering - Architecture - RHI - Dec 3, 2025When launching Unreal Engine with the Vulkan RHI, SM6 and RenderDoc Auto Attach on Startup enabled, the engine fails to initialize with the error: “A compatible Vulkan Driver is required to run the ...