I use Sent To Picard with <URLs> passed as the parameter and get the following exception. I had many albums selected; I imagine there is a limit of how long the parameter list can be when invoking a tool.
MusicBee v3.5.8249.26390D (Win10.0), 13 Sep 2022 13:27:
System.ComponentModel.Win32Exception (0x80004005): The filename or extension is too long
at System.Diagnostics.Process.StartWithShellExecuteEx(ProcessStartInfo startInfo)
at System.Diagnostics.Process.Start()
at #=zObqdaZsaRJXqcc75WA7AvB$8iFTA.#=zJUO6laY=.#=zpBwt1wpaAGqQ(Int32 #=z1pdpXpI=, IList`1 #=zGvnkKD4=)
at #=zObqdaZsaRJXqcc75WA7AvB$8iFTA.#=zJUO6laY=.#=zOKD_7mM=(ApplicationCommand #=z6IQrGvY=, Object #=zXBdTIBo=, IList`1 #=zGvnkKD4=)
at #=z2mtRg0T5lfphjIc5ZVI7b4m8YDAP.#=z6ykQ55Qp299O.#=z_vrsfiR1EkRZ(MouseEventArgs #=z614nzDw=)
at #=z2mtRg0T5lfphjIc5ZVI7b4m8YDAP.OnMouseClick(MouseEventArgs #=z614nzDw=)
at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
at System.Windows.Forms.Control.WndProc(Message& m)
at System.Windows.Forms.ScrollableControl.WndProc(Message& m)
at System.Windows.Forms.Form.WndProc(Message& m)
at #=zz_lnlPchTyLB8AnNzk9$UWA=.WndProc(Message& #=zF8Al2WA=)
at #=z2mtRg0T5lfphjIc5ZVI7b4m8YDAP.WndProc(Message& #=zF8Al2WA=)
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)