[MonoDevelop] Can't seem to create a new window in a C# project

[Anthony]

Hello Everyone,

I'm pretty new to MonoDevelop and I'm working with my very first project
in it. I started a new C# project then tried to add a GTK Window to it.
I got the following error:

System.ArgumentException: value
  at MonoDevelop.GtkCore.ReferenceManager.set_GtkPackageVersion
(System.String value) [0x00024] in
/builddir/build/BUILD/monodevelop-2.8.8.4/src/addins/MonoDevelop.GtkCore/MonoDevelop.GtkCore/ReferenceManager.cs:78

  at MonoDevelop.GtkCore.WidgetFileDescriptionTemplate.AddToProject
(MonoDevelop.Projects.SolutionItem policyParent,
MonoDevelop.Projects.Project project, System.String language,
System.String directory, System.String name) [0x00017] in
/builddir/build/BUILD/monodevelop-2.8.8.4/src/addins/MonoDevelop.GtkCore/MonoDevelop.GtkCore/WidgetFileDescriptionTemplate.cs:83

  at MonoDevelop.Ide.Templates.FileTemplate.CreateFile
(MonoDevelop.Ide.Templates.FileDescriptionTemplate newfile,
MonoDevelop.Projects.SolutionItem policyParent,
MonoDevelop.Projects.Project project, System.String directory,
System.String language, System.String name) [0x00006] in
/builddir/build/BUILD/monodevelop-2.8.8.4/src/core/MonoDevelop.Ide/MonoDevelop.Ide.Templates/FileTemplate.cs:366

  at MonoDevelop.Ide.Templates.FileTemplate.Create
(MonoDevelop.Projects.SolutionItem policyParent,
MonoDevelop.Projects.Project project, System.String directory,
System.String language, System.String name) [0x0002b] in
/builddir/build/BUILD/monodevelop-2.8.8.4/src/core/MonoDevelop.Ide/MonoDevelop.Ide.Templates/FileTemplate.cs:309

  at MonoDevelop.Ide.Projects.NewFileDialog.OpenEvent (System.Object
sender, System.EventArgs e) [0x000ab] in
/builddir/build/BUILD/monodevelop-2.8.8.4/src/core/MonoDevelop.Ide/MonoDevelop.Ide.Projects/NewFileDialog.cs:474


Any idea what this all means and how I can get around it to work on my
project?

Thanks!