UnrealEd 3.0 (UT2004): UKX packages randomly lose changes when saving

[>ExileD<]

Hi everyone,

I know this is a place related to UnrealEd 2, but I cant find a forum that isnt long dead about it, and since there isnt a specific room for UnrealEd 3.0 discussion I have decided to post here. If the moderators think I should post elsewere, they can tell me the more appropriate room and I'll be happy to post there.

I'm working on a UT2004 weapon replacement mod and I've run into a very strange problem with UnrealEd 3.0. I'm hoping someone with experience modding UT2004 might have seen this before.

I'm importing custom first-person weapon models (PSK + PSA) into a new `.ukx` package.

For each weapon I:

* Import the skeletal mesh.
* Import its animations.
* Link the animation set to the mesh.
* Rotate the mesh (Yaw = 49152). (my imports from blender are 90° wrong)
* Translate the mesh to the correct first-person position.
* Rename the animation sequences to match the names expected by UT2004 (`Idle`, `Fire`, `AltFire`, `Select`, `PutDown`, etc.).
* Assign the correct textures.

Everything works perfectly inside UnrealEd during the current session.

The problem:

When I save the package, UnrealEd appears to save successfully:

* it asks whether I want to overwrite the existing file;
* I click "Yes";
* the progress bar appears for a moment;
* no errors are reported.

However, after closing and reopening UnrealEd, only some of the modifications are actually present.

The strange part is that the missing changes seem completely random.

For example:

* One weapon keeps its textures while another loses them.
* Rotation may be saved for both weapons.
* Translation may only be saved for one.
* Animation sequence names are only partially saved.
* Existing objects also fail to save modified properties (for example changing a mesh translation or rotation on an already imported mesh).

Once a modification has failed to save, trying to apply it again usually produces the same result.

I've already tried:

* Creating a completely new package with a different name.
* Deleting the old package first.
* Re-importing everything from scratch.
* Importing fewer weapons.
* Saving after making all modifications in one session.
* Verifying the package is not read-only.
* Using only UnrealEd's Animation Browser (no ActorX tools).

The result is always similar: some changes are saved, others are silently discarded.

Additional information:

* UnrealEd 3.0 from UT2004.
* Windows 11.
* Meshes are imported successfully and work correctly while the editor is open.
* This is not a runtime problem; it happens before the game is even launched.
* The editor never reports any save errors.

Has anyone seen this behaviour before?

Is there a known limitation of the Animation Browser or the UKX package format, or some hidden step required before saving?

Any ideas would be greatly appreciated. I'm happy to provide more details if needed.

Thanks!