Created attachment 181842 [details]
Reproduction Steps

Summary
The latest version tends to crash when performing the "Pin to Animation Timeline" operation on complex layer structures.

Reproduction Steps
    Create a new image and add multiple layers and layer groups until the structure becomes relatively complex.

    Select all layers and layer groups, right-click, and choose the last option "Pin to Animation Timeline" from the context menu.

Observed Result
The software crashes with high probability.

Expected Result
The selected layers and layer groups should be pinned to the animation timeline.

Software/OS Version
Krita 5.2.9, installed via the official Windows installer.

摘要
	最新版本在复杂图层结构下执行“固定到动画时间轴”操作时易崩溃。

重现步骤
	1.新建图像，创建数个图层与图层组，直到它们的结构较为复杂
	2.全选图层和图层组并点击鼠标右键，在右键菜单中选择最后一项“固定到动画时间轴”

观察到的结果
	软件大概率会奔溃。

预期结果
	图层和图层组被固定到动画时间轴。

软件/操作系统版本
	使用Windows运行官方安装包安装的5.2.9版本。