CreateTask in Task group with Unobserved function call fails

[gabr42]

Reported by Saskathex, Nov 11, 2014

Following code produces on certain machines an error. The error happens sometimes but not all the times.

TaskGroup := CreateTaskGroup;
try
  for I := 0 to 2 do
    CreateTask (TestTask, Format ('TestTask %d', [I]))
      .SetParameter ('Number', I)
      .Unbserved
      .Join (TaskGroup);

  TaskGroup.RunAll;

Starting the tasks inside the Task Group Fails with the following stack trace:

OtlEventMonitor:221 (OtlEventMonitor.TOmniEventMonitor.Destroy) Access violation at address 0000000002060A36 in module 'ABC.exe'. Read of address 0000000000000000
[0000000002060A36] OtlEventMonitor.TOmniEventMonitor.Destroy (Line 221, "OtlEventMonitor.pas")
[0000000076D21278] KiUserExceptionDispatcher
[0000000002060A36] OtlEventMonitor.TOmniEventMonitor.Destroy (Line 221, "OtlEventMonitor.pas")
[000000000205E2DF] OtlTaskControl.TOmniTaskControlEventMonitor.Create (Line 3348, "OtlTaskControl.pas")
[0000000002061BE6] OtlEventMonitor.TOmniEventMonitorPool.Allocate (Line 414, "OtlEventMonitor.pas")
[000000000205E55D] OtlTaskControl.TOmniTaskControlEventMonitorPool.Allocate (Line 3379, "OtlTaskControl.pas")
[000000000205A114] OtlTaskControl.TOmniTaskControl.CreateInternalMonitor (Line 2491, "OtlTaskControl.pas")
[000000000205CD54] OtlTaskControl.TOmniTaskControl.Unobserved (Line 3045, "OtlTaskControl.pas")

Using Version 3.03b on an Windows Server 2008R2 64bit.

Removing the Unobserved function call works for us!