Mono/KeePass crashes on 'windows button press'

###---------- START KEEPASS ----------###

SendMessage (27263018, 0x112c, 0x4, 0x4)
SendMessage (27263012, 0x101f, (nil), (nil))
SendMessage (0, 0x1203, (nil), 0x7fffed13fc10)
SendMessage (0, 0x1204, (nil), 0x7fffed13fc10)
SendMessage (0, 0x1203, 0x1, 0x7fffed13fc10)
SendMessage (0, 0x1204, 0x1, 0x7fffed13fc10)
SendMessage (0, 0x1203, 0x2, 0x7fffed13fc10)
SendMessage (0, 0x1204, 0x2, 0x7fffed13fc10)
SendMessage (0, 0x1203, 0x3, 0x7fffed13fc10)
SendMessage (0, 0x1204, 0x3, 0x7fffed13fc10)
SendMessage (0, 0x1203, 0x4, 0x7fffed13fc10)
SendMessage (0, 0x1204, 0x4, 0x7fffed13fc10)

###---------- PRESS WINDOWS KEY ----------###

Stacktrace:

  at <unknown> <0xffffffff>
  at (wrapper managed-to-native) System.Windows.Forms.X11Keyboard.Xutf8LookupString (intptr,System.Windows.Forms.XEvent&,byte[],int,intptr&,System.Windows.Forms.XLookupStatus&) <0xffffffff>
  at System.Windows.Forms.X11Keyboard.LookupString (System.Windows.Forms.XEvent&,int,System.Windows.Forms.XKeySym&,System.Windows.Forms.XLookupStatus&) <0x000bb>
  at System.Windows.Forms.X11Keyboard.EventToVkey (System.Windows.Forms.XEvent) <0x0003f>
  at System.Windows.Forms.X11Keyboard.ToUnicode (int,int,string&) <0x00347>
  at System.Windows.Forms.X11Keyboard.TranslateMessage (System.Windows.Forms.MSG&) <0x00123>
  at System.Windows.Forms.XplatUIX11.TranslateMessage (System.Windows.Forms.MSG&) <0x00023>
  at System.Windows.Forms.XplatUI.TranslateMessage (System.Windows.Forms.MSG&) <0x0001f>
  at System.Windows.Forms.Application.RunLoop (bool,System.Windows.Forms.ApplicationContext) <0x00c73>
  at System.Windows.Forms.Form.ShowDialog (System.Windows.Forms.IWin32Window) <0x0087f>
  at System.Windows.Forms.Form.ShowDialog () <0x0000f>
  at (wrapper remoting-invoke-with-check) System.Windows.Forms.Form.ShowDialog () <0xffffffff>
  at KeePass.Forms.MainForm.OpenDatabase (KeePassLib.Serialization.IOConnectionInfo,KeePassLib.Keys.CompositeKey,bool) <0x0058f>
  at KeePass.Forms.MainForm.OnFormLoad (object,System.EventArgs) <0x0322c>
  at System.Windows.Forms.Form.OnLoad (System.EventArgs) <0x00071>
  at System.Windows.Forms.Form.OnLoadInternal (System.EventArgs) <0x0007f>
  at System.Windows.Forms.Form.OnCreateControl () <0x0004f>
  at System.Windows.Forms.Control.CreateControl () <0x0011f>
  at System.Windows.Forms.Control.WmShowWindow (System.Windows.Forms.Message&) <0x00163>
  at System.Windows.Forms.Control.WndProc (System.Windows.Forms.Message&) <0x002d3>
  at System.Windows.Forms.ScrollableControl.WndProc (System.Windows.Forms.Message&) <0x00013>
  at System.Windows.Forms.ContainerControl.WndProc (System.Windows.Forms.Message&) <0x0005b>
  at System.Windows.Forms.Form.WndProc (System.Windows.Forms.Message&) <0x00253>
  at KeePass.Forms.MainForm.WndProc (System.Windows.Forms.Message&) <0x001b4>
  at System.Windows.Forms.Control/ControlWindowTarget.OnMessage (System.Windows.Forms.Message&) <0x00024>
  at System.Windows.Forms.Control/ControlNativeWindow.WndProc (System.Windows.Forms.Message&) <0x00036>
  at System.Windows.Forms.NativeWindow.WndProc (intptr,System.Windows.Forms.Msg,intptr,intptr) <0x00310>
  at System.Windows.Forms.XplatUIX11.SendMessage (intptr,System.Windows.Forms.Msg,intptr,intptr) <0x003cf>
  at System.Windows.Forms.XplatUIX11.MapWindow (System.Windows.Forms.Hwnd,System.Windows.Forms.WindowType) <0x001df>
  at System.Windows.Forms.XplatUIX11.CreateWindow (System.Windows.Forms.CreateParams) <0x00bb3>
  at System.Windows.Forms.XplatUI.CreateWindow (System.Windows.Forms.CreateParams) <0x0001f>
  at System.Windows.Forms.NativeWindow.CreateHandle (System.Windows.Forms.CreateParams) <0x00033>
  at System.Windows.Forms.Control.CreateHandle () <0x00069>
  at System.Windows.Forms.Form.CreateHandle () <0x00027>
  at System.Windows.Forms.Control.CreateControl () <0x00087>
  at System.Windows.Forms.Control.SetVisibleCore (bool) <0x00083>
  at System.Windows.Forms.Form.SetVisibleCore (bool) <0x002ef>
  at KeePass.Forms.MainForm.SetVisibleCore (bool) <0x0009d>
  at System.Windows.Forms.Control.set_Visible (bool) <0x00032>
  at (wrapper remoting-invoke-with-check) System.Windows.Forms.Control.set_Visible (bool) <0xffffffff>
  at System.Windows.Forms.Application.RunLoop (bool,System.Windows.Forms.ApplicationContext) <0x002ef>
  at System.Windows.Forms.Application.Run (System.Windows.Forms.ApplicationContext) <0x00057>
  at System.Windows.Forms.Application.Run (System.Windows.Forms.Form) <0x00033>
  at KeePass.Program.Main (string[]) <0x00ae2>
  at (wrapper runtime-invoke) <Module>.runtime_invoke_void_object (object,intptr,intptr,intptr) <0xffffffff>

Native stacktrace:

	/usr/lib/libmonosgen-2.0.so.1(+0xcf1da) [0x7fe6335011da]
	/usr/lib/libmonosgen-2.0.so.1(+0x12cd7b) [0x7fe63355ed7b]
	/usr/lib/libmonosgen-2.0.so.1(+0x48016) [0x7fe63347a016]
	/usr/lib/libpthread.so.0(+0x10210) [0x7fe633226210]
	/usr/lib/libc.so.6(strlen+0x2a) [0x7fe632ef4b2a]
	/usr/lib/libX11.so.6(_XimLocalUtf8LookupString+0xeb) [0x7fe62bd09b1b]
	[0x40afa89e]

Debug info from gdb:


=================================================================
Got a SIGSEGV while executing native code. This usually indicates
a fatal error in the mono runtime or one of the native libraries
used by your application.
=================================================================

Aborted (core dumped)