why unfold failed

[arthur9188]

Engineering mode is not enabled. 16:55:41 Manual K-factor is being used: 0.40 (ansi) 16:55:41 exception at line 3367('Removing splitter failed',) 16:55:41 ('Removing splitter failed',) 16:55:41 Traceback (most recent call last): 16:55:41 File "C:\Users\Administrator\AppData\Roaming\FreeCAD\Mod\sheetmetal.\SheetMetalUnfolder.py", line 3367, in accept s, foldComp, norm, thename, err_cd, fSel, obN = getUnfold(k_factor_lookup) 16:55:41 File "C:\Users\Administrator\AppData\Roaming\FreeCAD\Mod\sheetmetal.\SheetMetalUnfolder.py", line 2645, in getUnfold TheTree = SheetTree(o.Object.Shape, f_number, k_factor_lookup) # initializes the tree-structure 16:55:41 File "C:\Users\Administrator\AppData\Roaming\FreeCAD\Mod\sheetmetal.\SheetMetalUnfolder.py", line 452, in init withoutSplitter = self.__Shape.removeSplitter() 16:55:41 Part.OCCError: Removing splitter failed 16:55:41

[luzpaz]

• Missing About info
• Missing example file (zip and uploaded to github)
• Missing step-by-step instructions on how to recreate the issue

[arthur9188]

https://github.com/arthur9188/freecad-danguidiao

[code]
OS: Windows 10 build 17763
Word size of FreeCAD: 64-bit
Version: 0.21.0.33345 (Git)
Build type: Release
Branch: master
Hash: a3c4f4bb01f5201daf666852444a8f9c5adbda8d
Python 3.10.11, Qt 5.15.8, Coin 4.0.0, Vtk 9.1.0, OCC 7.6.3
Locale: Chinese/China (zh_CN)
Installed mods: 
  * A2plus 0.4.60n
  * Assembly4 0.50.2
  * sheetmetal 0.2.63
[/code]