Came across this error, steps to reproduce;
Open a new tab while the sidebars are hidden, create a new playlist from the auto-opened left sidebar.
MusicBee v3.0.5874.38174 (Win10.0), 2 Feb 2016 14:42:
System.NullReferenceException: Object reference not set to an instance of an object.
at MusicBee.MusicBeeMain.#=quEO1fplKOL043KHeQm3ncw==.#=q3TruWClZNl$8oYIjnL8dJQ==(#=qveDAOvgLPdWcOC5xAIAR_BCpFxO$518fDyg$hD59$WzqCFflLFJsLNXUoJaD$5TY #=qIU0qJK3l4M2QEFKe$HreKg==)
at #=qqMazUzxbiJ8wC23ANBVbVZjozePuHjL7fjKkaH6f2DU=.#=qRZ92jERAG8H_Jt5nEJKVeg==(#=qxC8770vLtLm7MZ7wJL0XKQ== #=qD1gawmzG6d6iX$PgcYxHIA==)
at MusicBee.MusicBeeMain.#=qFUo5j0DNsaqoyFACj1DwLCxa_v6gelihQt0TJ0$T_ZM=(#=qtgNff1RzNdG6D5i2gRhy$4nX_ob6ULPUCDk3soGAtcU= #=qx50FCmCADQ5uAGetEdp1UA==, String #=qRKzQvT$l$hBfLmV3gQ4guQ==, List`1 #=qOEU3DiRbRNvgYNxPSlRGeg==)
at MusicBee.MusicBeeApplication.#=qnekbEoftJRya9PsqnPSyoA==.#=qrc880MMTC0lCoJ3W2OJNaA==(ApplicationCommand #=qqtGelIWwYClzHU3VEcG6VA==, Object #=q5s_XjWqWluNNI$5gw4rshA==, IList`1 #=qRDDZi9OjCiIuwqpBb_q6QQ==)
at #=qjq8F3Wc761y_vuUSzffqa3diZizzQX2u3bwuGg2fty0=.OnClick(EventArgs #=qX26NGuDnenlluYdA23jv$g==)
at System.Windows.Forms.ToolStripItem.HandleClick(EventArgs e)
at System.Windows.Forms.ToolStripItem.HandleMouseUp(MouseEventArgs e)
at System.Windows.Forms.ToolStripItem.FireEventInteractive(EventArgs e, ToolStripItemEventType met)
at System.Windows.Forms.ToolStripItem.FireEvent(EventArgs e, ToolStripItemEventType met)
at System.Windows.Forms.ToolStrip.OnMouseUp(MouseEventArgs mea)
at System.Windows.Forms.ToolStripDropDown.OnMouseUp(MouseEventArgs mea)
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.ToolStrip.WndProc(Message& m)
at System.Windows.Forms.ToolStripDropDown.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)