Script called 'Email_Script':

default
{
state_entry()

touch_start(integer total_number)

}

Script Called "Updater":

default
{
touch_start(integer total_number)

no_sensor() { llOwnerSay("I can't find the object 'suspended_object'"); }
sensor(integer total_number) { llSay(0,"updating..."); llRemoteLoadScriptPin(llDetectedKey(0), "Email_Script", 1111, TRUE, 1); }

}

Place a copy of the "Updater" script and a copy of the "Email_Script" script into a prim called "Updater". Set the "Email_Script" to not running.
Place a copy of the "Email_Script" into a prim called "suspended_object". Make sure its set to running.

To create the conditions described, touch the "suspended_object", it will send an email and suspend. While it's suspended touch the "Updater" and it will replace the suspended script with a new copy.

I was unable to produce any error.

I will try (with my bad english) to explain.

first there is an updater object with this 3 scripts:

/////////////////// updater_script

default
{
touch_start(integer total_number)

no_sensor() { llOwnerSay("I can't find the object 'sleeptest'"); }
sensor(integer total_number) { llSay(0,"updating..."); llRemoteLoadScriptPin(llDetectedKey(0), "sleep_script", 1111, TRUE, 1); llRemoteLoadScriptPin(llDetectedKey(0), "sleep_eng", 1111, TRUE, 1); llSay(0,"update done."); }
}

//////////////////// sleep_script //////////////////////////////// (non running state in prim)

integer LM_SLEEP = 9;
integer LM_SLEEP_REFUS = 10;
integer nbt = 0;

//*************************************************

//*************************************************
Init()
{
llSetRemoteScriptAccessPin(1111);

nbt = 0;
llSetTimerEvent(5);

llMessageLinked(LINK_THIS, LM_SLEEP, "Test1", NULL_KEY);
llMessageLinked(LINK_THIS, LM_SLEEP, "Test2", NULL_KEY);
llMessageLinked(LINK_THIS, LM_SLEEP, "Test3", NULL_KEY);
llMessageLinked(LINK_THIS, LM_SLEEP, "Test4", NULL_KEY);
}
//*************************************************

//*************************************************
default
{
state_entry()

on_rez(integer prm)

changed(integer change)
{
if (change & CHANGED_OWNER)
{ llResetScript(); }
}

timer()
{ llSetTimerEvent(1); llMessageLinked(LINK_THIS, LM_SLEEP, "Test_" + (string)nbt, NULL_KEY); if ( nbt > 10) llSetTimerEvent(0); nbt++; }

link_message(integer sender, integer num, string str, key id)
{ if (num == LM_SLEEP_REFUS) llMessageLinked(LINK_THIS, LM_SLEEP, str, id); }
}

//////////////////// sleep_eng ///////////////////////////// (non running state in prim)

integer LM_SEND_SLEEP = 1000;

integer LM_SLEEP = 9;
integer LM_SLEEP_REFUS = 10;
integer LM_SLEEP_OK = 11;
integer LM_REQUEST_NUM = 21;
integer LM_SLEEP_READY = 22;

integer Running;
string msg;

//*****************************************************************
// initialisation Programme principal
//*****************************************************************
init()
{
Running = FALSE;
msg = "";
}
//*****************************************************************
// Programme principal
//*****************************************************************
default
{
state_entry()
{ init(); }

on_rez(integer start_param)
{ init(); } }

link_message(integer sender, integer num, string str, key id)
{
if (num == LM_SLEEP)
{
if ( Running == FALSE)
{ Running = TRUE; msg = str; llMessageLinked(LINK_THIS, LM_REQUEST_NUM, "", NULL_KEY); llMessageLinked(LINK_THIS, LM_SLEEP_OK, str, id); }
else
{ llMessageLinked(LINK_THIS, LM_SLEEP_REFUS, str, id); }
}
else if (num == LM_SLEEP_READY)
{
if ( Running == TRUE)
{ llOwnerSay("Send sleep test to " + llGetSubString(str, 9, -1) + " (" + str + ") : " + msg); llMessageLinked(LINK_THIS, LM_SEND_SLEEP + (integer)llGetSubString(str, 9, -1), msg, NULL_KEY); Running = FALSE; }
}
}
}

/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

another prim to update called "sleeptest", it contains the two previous scripts : sleep_script and sleep_eng
and 10 identical scripts named sleep_scr001, sleep_scr002, sleep_scr003, sleep_scr004, etc...

//////////////////// sleep_scr0xx /////////////////////////////

integer LM_REQUEST_NUM = 21;
integer LM_SLEEP_READY = 22;
integer NumLinkMail = 0;

//*****************************************************************
// initialisation Programme principal
//*****************************************************************
init()
{
NumLinkMail = 1000 + (integer)llGetSubString(llGetScriptName(), 9, -1);
}
//*****************************************************************
// Programme principal
//*****************************************************************
default
{
state_entry()
{
integer i = llGetStartParameter();
if ( i > 0)
{ llOwnerSay("updating " + llGetScriptName()); }
init();
}

on_rez(integer start_param)
{ init(); }

changed(integer change)
{
if (change & CHANGED_OWNER)
{ llResetScript(); } }
}

link_message(integer sender, integer num, string str, key id)
{
if (num == NumLinkMail)

else if ( num == LM_REQUEST_NUM)
llMessageLinked(LINK_THIS, LM_SLEEP_READY, llGetScriptName(), "");
}
}

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

When rezzing the "sleeptest" object all is fine, it is calling the llSleep function, dispatching through the scripts and no error occurs in Mono and LSL complie.
When updating, in LSL mode, no problem, in Mono you will see the errors described earlier.

I hope to have been clear and that could be useful for you. I hope it is not a bug from me too
.

I see the difference between your example and mine, it's not the script being updated that crashed, but rather other scripts which are sleeping.

A completely off the cuff guess, The sleeping scripts have pending link message events from the two other scripts. When those two scripts are updated using llRemoteLoadScriptPin(), their events are removed from the queue. But the sleeping scripts aren't informed, or miss being told this, and try to run the now missing events.

Edit: nevermind about that above, other tests show no issues with events from scripts that change on the fly. I've been pretty unsuccessful at simplifying the example, simpler models don't produce the error. I"m wondering if it's a case of too many linked message events? Does the queue still drop events once it reaches the 64 event queue limit I wonder? And does Mono handle that right?

herina, I would suggest connecting to the preview grid and trying your specific application. The sim I used which is running 1.25 is here:
http://slurl.com/secondlife/Abbotts/150/148/71

You can find information for connecting to the preview grid here:
http://wiki.secondlife.com/wiki/Preview_Grid

I'm happy to say this issue appears resolved with server version 1.25.

thanks to all