Hello everyone,
I am developing a plugin using the SolidWorks API and encountered an issue while copying a width mate feature. The matedata.TabSelection is null, causing the mate feature creation to fail. Below is the relevant code snippet:

private void CopyWidthMate(DesignObject srcDesignObject, DesignDoc targetDoc, DocMap docMap, DesignObject targetParent)
{
   IAssemblyDoc assembly = (IAssemblyDoc)targetDoc.swModel;
   WidthMateFeatureDataInfo widthdata = (WidthMateFeatureDataInfo)this.mateFeatureData;
   WidthMateFeatureData matedata = assembly.CreateMateData((int)this.MateType);
   matedata.ConstraintType = widthdata.widthMateData.ConstraintType;
   if (matedata.ConstraintType == (int)swMateWidthOptions_e.swMateWidth_Dimension)
   {
       matedata.DistanceFromEnd = widthdata.widthMateData.DistanceFromEnd;
       matedata.FlipDimension = widthdata.widthMateData.FlipDimension;
   }

   Face2[] all = new Face2[widthdata.WidthSelection.Count + widthdata.TabSelection.Count];
   int count = 0;
   Face2[] widthsel = new Face2[widthdata.WidthSelection.Count];
   for (int i = 0; i < widthdata.WidthSelection.Count; i++)
   {
       DesignObject srcObj1 = docMap.LeftDoc.SearchDesignObjectOfInteraface(widthdata.WidthSelection[i].Interface);
       DesignObject targetObj1 = docMap.LeftToRight(srcObj1);
       widthsel[i] = (Face2)targetObj1.FeatureObject.Interface;
       all[count] = widthsel[i];
       count++;
   }
   Face2[] tabSel = new Face2[widthdata.TabSelection.Count];
   for (int i = 0; i < widthdata.TabSelection.Count; i++)
   {
       DesignObject srcObj1 = docMap.LeftDoc.SearchDesignObjectOfInteraface(widthdata.TabSelection[i].Interface);
       DesignObject targetObj1 = docMap.LeftToRight(srcObj1);
       tabSel[i] = (Face2)targetObj1.FeatureObject.Interface;
       all[count] = tabSel[i];
       count++;
   }

   targetDoc.swModel.ClearSelection2(true);
   SelectionMgr selmrg = (SelectionMgr)targetDoc.swModel.SelectionManager;
   SelectData seldata = selmrg.CreateSelectData();
   seldata.Mark = 1;
   int n2 = targetDoc.swModel.Extension.MultiSelect2(widthsel, true, seldata);
   matedata.WidthSelection = widthsel;

   SelectData seldata2 = selmrg.CreateSelectData();
   seldata2.Mark = 16;
   int n1 = targetDoc.swModel.Extension.MultiSelect2(tabSel, true, seldata2);
   int selectedCount = targetDoc.swModel.ISelectionManager.GetSelectedObjectCount();

   // Ensure tabSel array contains valid Face2 objects
   for (int i = 0; i < tabSel.Length; i++)
   {
       tabSel[i] = (Face2)selmrg.GetSelectedObject6(i + 1, -1);
   }

   matedata.TabSelection = tabSel;

   Feature feature = assembly.CreateMate(matedata);
   if (feature == null)
   {
       throw new Exception("CreateMate failed when copying " + srcDesignObject);
   }
}

In the above code, I attempt to select faces using the MultiSelect2 method and assign them to matedata.TabSelection. However, matedata.TabSelection remains null, causing the mate feature creation to fail.
I have checked that the tabSel array is correctly populated and ensured that it contains valid Face2 objects after the MultiSelect2 method call, but the issue persists.

Environment Information:

•    SolidWorks Version: 2023
•    .NET Framework Version: 4.8
•    Development Environment: Visual Studio 2022
•    Programming Language: C#