Floating Style Editor pane breaks changing Rooms

What's the bug?

Hi all,

On the latest Nightly build, if I change to another Room while the Style Editor is floating, the room won't appear to change. I can click around and open a few windows. Hovering over menu buttons no longer light up, and can't interact with panes like the Viewer.

From the several floating windows I've tried, only the Style Editor appears to cause this. What tab in the Style Editor is open (Color, Settings, etc.) doesn't effect the outcome. If the Style Editor is docked, not floating, this bug doesn't happen. Upon quitting and restarting OpenToonz, it will open on the last room I clicked on, even if I don't see the Room change during the last session the bug occurred.

When I quit OpenToonz after this bug occurs, there is a random chance of the user session crashing abruptly, taking me back to the LightDM login screen. This never seems to happen the first time in a user session however, only from the second time, but that may have just been luck.

I compile OT myself because I like to apply the patch to fix choppy brush lines in Linux, but this even happens with a completely fresh build, including the original configs from /stuff.

The stdout of OpenToonz from the terminal is inconsistent. Here's one from when the user session crashed, logging me out: [ThemeManager:::preloadIconMetadata] STARTED with path: ":/icons" Global QPixmapCache cleared qt.qpa.xcb: QXcbConnection: XCB error: 3 (BadWindow), sequence: 1590, resource id: 13077223, major code: 40 (TranslateCoords), minor code: 0 QLayout: Attempting to add QLayout "" to ParamViewer "", which already has a layout QLayout: Attempting to add QLayout "" to QWidget "", which already has a layout

After a dozen or so recreations of this bug, I finally got a 'OpenToonz crashed unexpectedly' message (usually it would just close like normal, or crash the user session). This didn't crash the user session.

OS: Linux Mint 21.3 XFCE (X11) GPU: NVIDIA RTX 3060

Thanks.

Steps to Reproduce

1. Load a scene.
2. Open Style Editor, making sure it's floating.
3. Attempt to change rooms.
4. Quit.

What did you expect to happen?

Floating panes usually continue to float in front of whatever Room you switch to.

Screenshots, Videos or Crash Logs

Crash-20260412-212858.log

OpenToonz Version

Nightly (specify below)

Exact Version Info (optional)

built April 12, 2026

Operating System

Linux

GPU Brand

NVIDIA

Graphics Tablet

None