When I open the Security Editor, i have a localization error message. After closing the error, the security editor is open and the labels are in French!

I know that my desktop is in French (Regional Settings in "French - Canada"), but I am used to code in English. Since I did not set anything for the Localization & Messages (My broken rules are in french now when using the Security Editor), it is a bug in the framework or do i need to set something to avoid that error?

No, this by design.  It is assumed that if your regional settings are set to French then the displayed language will be in French as well.  You can control this at run-time, however this is set automatically at design-time.

This is one of the new features...all run-time components have been pre-localized in 7 languages.  since the Security editor is a run-time component which you can present to your end-users, it falls into this category.

Source     : MicroFour StrataFrame Base

Stack Trace:
   at MicroFour.StrataFrame.UI.Localization.ThrowKeyNotFoundException(String Key)
   at MicroFour.StrataFrame.UI.Localization.GetKeyRowFromXml(String Key)
   at MicroFour.StrataFrame.UI.Localization.RetrieveTextValue(String TextValueKey)
   at MicroFour.StrataFrame.Security.SecurityMain.SecurityMain_Load(Object sender, EventArgs e)
   at System.EventHandler.Invoke(Object sender, EventArgs e)
   at System.Windows.Forms.Form.OnLoad(EventArgs e)
   at MicroFour.StrataFrame.UI.Windows.Forms.BaseForm.OnLoad(EventArgs e)
   at System.Windows.Forms.Form.OnCreateControl()
   at System.Windows.Forms.Control.CreateControl(Boolean fIgnoreVisible)
   at System.Windows.Forms.Control.CreateControl()
   at System.Windows.Forms.Control.WmShowWindow(Message& m)
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.ScrollableControl.WndProc(Message& m)
   at System.Windows.Forms.ContainerControl.WndProc(Message& m)
   at System.Windows.Forms.Form.WmShowWindow(Message& m)
   at System.Windows.Forms.Form.WndProc(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

Thanks, Trent!