Taskbar Bug in Windows 11 24H2

[luciano_f]

I'm a Delphi programmer, and about six months ago, I noticed a strange error in both Delphi and several other applications, such as Snagit, that would freeze.

To identify the cause, I disabled several applications until I realized that "Startallback windows 11" was the culprit. It also freezes when I access the settings and doesn't respond.

The Delphi code I use to locate the taskbar's position is this one, which returns without a position after the error.
 

function GetTaskBarSize: Integer;
Var Data: TAppBarData;
Begin
 Result := 0;

 Data.cbSize := SizeOf(TAppBarData);

 If SHAppBarMessage(ABM_GETTASKBARPOS, Data) = 1 Then
  Result := Data.rc.Bottom - Data.rc.Top;

end;

function GetTaskBarAlignment: TAlign;
var
 Data: TAppBarData;
 ScrW, ScrH: Integer;
begin
 Result := alNone;

 Data.cbSize := SizeOf(TAppBarData);
 ScrW := Screen.Width;
 ScrH := Screen.Height;

 if SHAppBarMessage(ABM_GETTASKBARPOS, Data) = 1 then Begin
  if (Data.rc.Top > ScrH div 2) and (Data.rc.Right >= ScrW) then
   Result := alBottom
  else
   if (Data.rc.Top < ScrH div 2) and (Data.rc.Bottom <= ScrW div 2) then
    Result := alTop
   else
    if (Data.rc.Left < ScrW div 2) and (Data.rc.Top <= 0) then
     Result := alLeft
    else
     Result := alRight;
 End;

end;

 

[Tihiy]

Well you better tell what needs to be done to trigger hung or find where hung is - capture dump or find in debugger directly attached to problematic process

Edited 1 hour ago by Tihiy

[Tihiy]

Most likely hang is in SHAppBarMessage call, so take explorer.exe process dump to analyze