Issue with MTBF MTTR..!!

I am having this strange issue. I have three operators assigned to one break for which I am using the MTBF MTTR. Most of the times it works fine and breaks are called for all three operators but sometimes break is not called on one or more operators and I end up getting an error message as the model is unable to find the downobject and so whatever commands use it as a node are not executed properly. Is this a bug with flexsim or is it something I am missing.
I have attached the model. If you run it a few times until break 1 (at 20 minutes) u might be able to see the error message.

That model doesn't seem to give the error you describe. Can you check again?

As I said.. The error is a bit random.. It may happen it may not happen.. MOst probably it looks like a bug with Flexsim cause if I wrote a bad code it should either happen or not happen.. Correct me if I am wrong

When trying to find a bug in your model like this the first thing to do is find out why it's not repeating. Repeatability means using the same random numbers and all starting conditions are the same.

Can you check that the rest of your model repeats perfectly? A common thing to overlook is setting the reset positions of task executors that are not on networks. Any labels or variables you've added may need to be reset too. Once you've got a repeatable model it's usually much easier to debug.

Yes, I have looked at the model and if you do too then u ll find it is repeatable. What happens occasionally is when the MTBF MTBR trigger is fired the downobject pointer which should return the Task-executor returns NULL and that is why the following code returns null.
As I see it its not a problem with repeatability because if a certain number of operators are assigned to a MTBF MTBR trigger it should be able to point towards those operators every time. There is no condition specified anywhere that the downobject pointer should return NULL in a particular case.. If you see in the model I have not selected any states where the MTBF trigger does or does not apply.

What happens occasionally is when the MTBF MTBR trigger is fired the downobject pointer which should return the Task-executor returns NULL and that is why the following code returns null.

I ran the model you posted at least 50 times without repeating random streams and what you describe above never happened. Insert the following code after downobject is passed into the Down Function (after line 3) and let us know when your model stops and displays the message. Make sure Repeat Random Streams is ON. If it does not happen during the run, go to the Experimenter Advanced tab and increment the "Repeat Streams of Replication" value and try again. Eventually (if you what you claim is true) there will be a replication that always displays the message at the same run time, then you can report back to us with the details.

if(!objectexists(downobject))
{
	msg("error","it happened",1);
	stop();
}