Crash on Mac on exit.

Media Framework - Aug 17, 2020

A licensee reported trouble with a crash on exit on Mac. They discovered that the file AvfMediaPlayer.cpp, on the function Open there is this piece of code:// Force the AV player to not be able to ...

Using the Execute Console Command node to run demoplay causes the editor crash/freeze

UE - Networking - Nov 13, 2015

This bug has different behavior throughout the 4 different versions listed. 4.8.3 - Gives an assert 4.9.2 & 4.10 - Gives a fatal error crash 4.11 (Main) - Freezes the editor without a crash report ...

Failed Import Error Message Appears on Components in Child Blueprints

UE - Gameplay - Components - Dec 2, 2015

Creating a C++ class based on actor and adding components to it will build successfully and work as expected. However, creating two child blueprints of a parent that is based on that C++ class and p ...

Content is Missing from Cook and indeterminism: StaticMeshComponents in Blueprints that copy data into themselves from StaticMesh have indeterminism due to StaticMesh not yet finished loading, postloading, or building

UE - Core - Systems - Nov 12, 2025

Content is Missing from Cook warnings are warnings reported at the end of cook phase of a project's data build. They report that data used by a cooked package will not be available at runtime. This ...

Using Tortoise SVN causes the engine's source control to be inconsistent

Tools - Jun 16, 2015

If a user decides to use Tortoise SVN, the error messages given for needing to have things checked out is inconsistent. If there is a blueprint which references another blueprint, and the reference ...

Actors not marked as Always Relevant do not replicate to Clients that have possessed a vehicle past 15,000 units of the point of possession

UE - Networking - Oct 20, 2015

Actors not marked as Always Relevant do not replicate to Clients that have possessed a vehicle past 15,000 units (the sq root of Net Cull Distance Squared) of the point of possession. Note that repl ...

UE4Editor_SlateCore!TSharedFromThis<SWidget,0>::AsShared() sharedpointer.h:1221

Tools - Apr 18, 2017

This bug report was entered as new crash groups appeared linking to [Link Removed] which was marked as fixed for 4.15.1 and the previous reproduction did not reproduce the issue Error message: Ass ...

Float Curve evaluation may yield completely wrong results due to floating-point precision issue

UE - Runtime - Animation - Oct 31, 2024

Note: This is possibly related to [Link Removed] To Do . For some inputs, function UE::Curves::WeightedEvalForTwoKeys() ins ...

Reference to control rig can be lost on actors with multiple skeletal mesh components

zComponent - Archive - Apr 4, 2023

In the attached project, when we initially add a control rig track for the actor with multiple skeletal mesh components, we add the control rig for the correct component because FControlRigParameter ...

Changing blueprint default values inside arrays only updates loaded child blueprints

UE - Core - Systems - Jul 30, 2020

The rules for delta serialization in UE4 are complicated, and the editor tries to hide them from you, which works 90% of the time but can lead to confusion and data loss in other situations. In the ...