Tried using Shift + del, after pressing enter...
...An error has occurred.
System.NullReferenceException: Object reference not set to an instance of an object.
at osu.GameModes.SongSelectionMenu.optionDeleteBeatmap(Object sender, EventArgs e)
at osu.GameModes.SongSelectionMenu.GameBase_OnKeyRepeat(Object sender, Keys k, Boolean first)
at osu.Input.KeyboardHandler.RepeatKeyEventHandler.Invoke(Object sender, Keys k, Boolean first)
at osu.Input.KeyboardHandler.DoKeyPressed(Keys k)
at osu.Input.InputManager.UpdateFrame()
at osu.GameBase.Update(GameTime gameTime)
at Microsoft.Xna.Framework.Game.Tick()
at Microsoft.Xna.Framework.Game.HostIdle(Object sender, EventArgs e)
at Microsoft.Xna.Framework.GameHost.OnIdle()
at Microsoft.Xna.Framework.WindowsGameHost.ApplicationIdle(Object sender, EventArgs e)
at System.Windows.Forms.Application.ThreadContext.System.Windows.Forms.UnsafeNativeMethods.IMsoComponent.FDoIdle(Int32 grfidlef)
at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(Int32 dwComponentID, Int32 reason, Int32 pvLoopData)
at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
at System.Windows.Forms.Application.Run(Form mainForm)
at Microsoft.Xna.Framework.WindowsGameHost.Run()
at Microsoft.Xna.Framework.Game.Run()
at osu.Program.Main()