Attempting to use a ttk.Frame with wm_manage() causes a TclError:

_tkinter.TclError: window ".!frame" is not manageable: must be a frame, labelframe or toplevel

The (Tcl) documentation for wm manage states "Only frame, labelframe and toplevel widgets can be used with this command." One might reasonably expect a ttk.Frame to appropriately fall under this requirement, especially since the name 'frame' is used for them, but it does not. One must use a tk.Frame instead to make this work.

At the very least, this needs to be documented. Looking at the error message and seeing it complain that a 'frame' is not one of 'frame', 'labelframe' or 'toplevel' is extremely confusing. There is nothing to lead to the conclusion that a ttk Frame is not a 'frame'. Better than documenting it, of course, would be to make wm_manage actually work properly with a ttk.Frame, as developers would expect.