Family Load error using NewFamilyInstance

[Anonymous]

I'am loading attached families through c# api code in Revit 2015. But each time I get

"A serious error has occurred. It is strongly recommended that you use Save As to save your work in a new file before continuing."  this message. 

Manually those families  are loaded successfully.

I can't figure out the issue.

[BIM.Frankliang]

Hi chakrabortyambar,

     I don't know how do you use C# RevitAPI to load family. You could try to use codes below:

  public Family LoadFamily(Autodesk.Revit.DB.Document doc, string familyPath)
  {
       try
       {
           Family family = null;
           var rfaFileName = Path.GetFileNameWithoutExtension(familyPath);
           if (new FilteredElementCollector(doc).OfClass(typeof(Family)).Count(m => m.Name == 
               rfaFileName) == 0)
           {
               if (!File.Exists(familyPath))
               {
                   return null;
               }
               doc.LoadFamily(familyPath, out family);
               if (family == null)
               {
                   List<Family> families = new FilteredElementCollector(doc).OfClass(typeof(Family)).ToElements().Cast<Family>().Where(f => f.Name == rfaFileName).ToList();
                   if (families.Count > 0)
                   {
                       family = families.FirstOrDefault();
                   }
               }
           }
           else
           {
               family = new FilteredElementCollector(doc).OfClass(typeof(Family)).FirstOrDefault(m => m.Name == rfaFileName) as Family;
           }
           return family;
    }
    catch (Exception ex)
    {
        return null;
    }
}

Note that codes must run in Transaction 🙂