Ломается .dll при понижении версии платформы

System.BadImageFormatException
  HResult=0x8007000B
  Сообщение = Не удалось загрузить файл или сборку "SignatureLib, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null" либо одну из их зависимостей. Была сделана попытка загрузить программу, имеющую неверный формат.
  Источник = WindowsForms
  Трассировка стека:
   at WindowsForms.WordManager.CreateDoc(DirectoryHP DirHP) in D:\Projects\WindowsFormsSequence\WindowsForms\WordManager.cs:line 596
   at WindowsForms.NewMainForm.Open_Menu_Click(Object sender, ItemClickEventArgs e) in D:\Projects\WindowsFormsSequence\WindowsForms\NewMainForm.cs:line 115
   at DevExpress.XtraBars.BarItem.OnClick(BarItemLink link)
   at DevExpress.XtraBars.BarButtonItem.OnClick(BarItemLink link)
   at DevExpress.XtraBars.BarItemLink.OnLinkClick()
   at DevExpress.XtraBars.BarButtonItemLink.OnLinkAction(BarLinkAction action, Object actionArgs)
   at DevExpress.XtraBars.ViewInfo.BarSelectionInfo.ClickLink(BarItemLink link)
   at DevExpress.XtraBars.ViewInfo.BarSelectionInfo.UnPressLink(BarItemLink link)
   at DevExpress.XtraBars.Ribbon.Handler.BaseRibbonHandler.OnUnPressItem(DXMouseEventArgs e, RibbonHitInfo hitInfo)
   at DevExpress.XtraBars.Ribbon.Handler.BaseRibbonHandler.OnMouseUp(DXMouseEventArgs e)
   at DevExpress.XtraBars.Ribbon.Handler.RibbonHandler.OnMouseUp(DXMouseEventArgs e)
   at DevExpress.XtraBars.Ribbon.RibbonControl.OnMouseUp(MouseEventArgs e)
   at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
   at System.Windows.Forms.Control.WndProc(Message& m)
   at DevExpress.Utils.Controls.ControlBase.WndProc(Message& m)
   at DevExpress.XtraBars.Ribbon.RibbonControl.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
   at DevExpress.Utils.Drawing.Helpers.NativeMethods.UnsafeNativeMethods.DefSubclassProc(IntPtr hWnd, IntPtr Msg, IntPtr wParam, IntPtr lParam)
   at DevExpress.Utils.Drawing.Helpers.Win32SubclasserFactory.Win32Subclasser.SubClassProcInner(IntPtr hWnd, IntPtr Msg, IntPtr wParam, IntPtr lParam, IntPtr uIdSubclass, IntPtr dwRefData)
   at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
   at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(IntPtr dwComponentID, Int32 reason, Int32 pvLoopData)
   at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
   at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
   at WindowsForms.Program.Main() in D:\Projects\WindowsFormsSequence\WindowsForms\Program.cs:line 19