I can only see the multiple artists plugin in Advanced search and replace box. I did delete most of the versions of the leadind zero's plugin except the version i may still use at some time. They appear to still be in the folder, just not visible in your plugin.
I am also getting this error when I close out of the plugin, and have to ctrl alt del to get out. I am on win 7 64bit
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MusicBee v1.3.4249.15886 (Win6.1), 21 Aug 2011 14:32:
System.ArgumentOutOfRangeException: Not a valid Win32 FileTime.
at System.DateTime.ToFileTimeUtc()
at System.IO.File.SetLastWriteTimeUtc(String path, DateTime lastWriteTimeUtc)
at System.IO.FileSystemInfo.set_LastWriteTimeUtc(DateTime value)
at MusicBeePlugin.AdvancedSearchAndReplacePlugin.saveSettings()
at MusicBeePlugin.AdvancedSearchAndReplacePlugin.buttonCancel_Click(Object sender, EventArgs e)
at System.Windows.Forms.Control.OnClick(EventArgs e)
at System.Windows.Forms.Button.OnClick(EventArgs e)
at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)
at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
at System.Windows.Forms.Control.WndProc(Message& m)
at System.Windows.Forms.ButtonBase.WndProc(Message& m)
at System.Windows.Forms.Button.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)