GNOME Shell stall after “Trying to operate on an unmanaging window” error in `moveHandler.js` (Fedora 43, GNOME 49, Wayland)

Describe the bug

GNOME Shell freezes while moving or interacting with windows when the Tiling Assistant extension is enabled. The system froze(approx 5 min) and I had to shut off power as none of the commands worked including alt + F3. This hasn't happened to me in the 2 days since I installed Fedora along with the tiling window manager.

The journal shows a JavaScript error from the extension:

Error: Trying to operate on an unmanaging window

The error originates from moveHandler.js. Immediately after the error appears, GNOME Shell’s event loop appears to stall and input processing begins to lag. The desktop becomes unresponsive (mouse and keyboard lag).

Steps to reproduce

1. Enable the Tiling Assistant extension
2. Use GNOME normally (move or tile windows)
3. At some point GNOME briefly freezes
4. journalctl shows an extension error followed by input lag warnings

Observed behavior

GNOME Shell becomes unresponsive.

Journal logs show:

JS ERROR: Error: Trying to operate on an unmanaging window!
initialize/assertExistenceFor/</window.assertExistence
file:///home/nikil/.local/share/gnome-shell/extensions/tiling-assistant@leleat-on-github/src/extension/tilingWindowManager.js:36:31
_onMoveFinished
file:///home/nikil/.local/share/gnome-shell/extensions/tiling-assistant@leleat-on-github/src/extension/moveHandler.js:219:20
_onMoveStarted
file:///home/nikil/.local/share/gnome-shell/extensions/tiling-assistant@leleat-on-github/src/extension/moveHandler.js:211:26

Shortly after:

libinput error: event processing lagging behind by 109ms, your system is too slow
libinput error: event processing lagging behind by 314ms, your system is too slow

Expected behavior

GNOME Shell should remain responsive when moving or tiling windows.

Environment

Distro: Fedora Linux 43 (Workstation Edition)
GNOME Shell: 49.4 (mutter 49.4)
Session: Wayland

GPU:

Intel TigerLake-H GT1 [UHD Graphics] (primary renderer)
NVIDIA GA107 [GeForce RTX 2050]

00:02.0 VGA compatible controller: Intel Corporation TigerLake-H GT1 [UHD Graphics] (rev 01)
01:00.0 3D controller: NVIDIA Corporation GA107 [GeForce RTX 2050] (rev a1)

Relevant journal logs

JS ERROR: Error: Trying to operate on an unmanaging window!
initialize/assertExistenceFor/</window.assertExistence
.../tilingWindowManager.js:36:31
_onMoveFinished
.../moveHandler.js:219:20
_onMoveStarted
.../moveHandler.js:211:26

libinput error: event processing lagging behind by 109ms, your system is too slow
libinput error: event processing lagging behind by 314ms, your system is too slow

Start with src/extension/moveHandler.js around _onMoveStarted and _onMoveFinished, then inspect src/extension/tilingWindowManager.js around line 36 where the unmanaging-window error is reported. Reproduce window moving or tiling with Tiling Assistant enabled and use the journal output to assess the stall; done means GNOME Shell remains responsive without this error.