NotImplementedException thrown by project.ProjectItems.AddFolder

[sapsari]

Describe the bug
Client receives following error, dont know his setup or project info. No other errors

System.NotImplementedException: The method or operation is not implemented.
at EnvDTE.ProjectItems.AddFolder(String Name, String Kind)

AddAnyFile/src/Helpers/ProjectHelpers.cs

Line 169 in ea2c57a

ProjectItem item = existing ?? project.ProjectItems.AddFolder(list.First());