Placing down "Invisible Target Soldier/Vehicle/Airplane" causes crash on dedicated server.

[PineCone227]

Mods:
Modlist attached as PDF file (converted HTML file from launcher)
Arma 3_mods.pdf

• Arma 3: 2.02.0.147447 Profiling Branch [e.g. 1.00 stable, rc, dev]
• CBA: v3.15.3.210310 [e.g. 3.0.0 stable, commit hash]
  Make sure to reproduce the issue with only CBA on a newly created mission!

Description:
Attempting to use the invisible target units of any side results in a server crash. RPT log file attached.

Steps to reproduce:

• Access zeus on server
• Place down Invisible Target Soldier
• The server crashes with exception code C0000005 ACCESS_VIOLATION

Expected behavior:
Server does not crash and Invisible Target units are able to be used in mission making.

Where did the issue occur?

• Dedicated

Log Files:
arma3server_x64_2021-03-17_13-33-09.txt

Additional context:
This has also happened a few months before with a completely different set of mods (and a much smaller one). Note that this doesn't mean the issue has been appearing and reappearing over time, but just that no one used the target units so no crashes, or lack thereof could've been reported.
Screenshots:
None

[commy2]

RPT file with only CBA_A3 would be helpful. This has 1000 and 1 mods.

[PineCone227]

I'll try making a clean dedicated server instance and replicating the issue when I get the chance. I was aware that submitting an incident happening with this many mods isn't that helpful, but felt that it should be reported either way.

[PineCone227]

I managed to reproduce the crash with only CBA running on both client and server. Fresh server profile and official ZGM 48+2 mission on Altis. Here is the RPT:
arma3server_x64_2021-03-20_17-30-58.txt

[PineCone227]

Any updates? I'd just like to know you've seen it.

[dedmen]

Can confirm.
I have a repeated crash on one specific mission, where Arma crashes while a vehicle gunner tries to target a CBA Invisible Target Soldier.
But I have absolutely no clue why.
I think its related to a bad WW2 mod vehicle.

[PineCone227]

I think its related to a bad WW2 mod vehicle.

Im not sure about the accuracy of your statement since for me the crash can be reproduced on any given mission with no other units on the map and with nothing but CBA_A3 itself loaded. I've never used any WW2 mod.
Then again you're the programmer here and im just an IT student who runs a 3 player server.

[TheCandianVendingMachine]

I have the same crash when spawning an invisible CBA target of any type. My crash happens when soldiers target an invisible target

[commy2]

Are these invisible guys any good anyway? Anyone here wants to use them or could just just be sacked for good?

[TheCandianVendingMachine]

If the crash didn't exist, this would be a core feature for AI mods imo. It also is probably an engine issue, because in further testing the vehicle itself doesn't cause the crash but rather a unit being inside the vehicle does.

[jonpas]

Maybe @dedmen has any idea or time to look at the crash dumps?

[ToxaBes]

I have same issue with CBA invisible target on Linux dedicated servers (both 32 and 64-bit). Local playing is ok, only dedicated mode affected. I have coredump but can't debug it because gdb said: (No debugging symbols found in /home/steam/arma3/arma3server_x64) and backtrace looks like:

#0  0x00000000018ba807 in ?? ()
#1  0x00000000018ba2d4 in ?? ()
#2  0x00000000017adb94 in ?? ()
#3  0x00000000018b25c7 in ?? ()
#4  0x00000000018ca8c7 in ?? ()
#5  0x00000000018caa24 in ?? ()
#6  0x0000000000a2a615 in ?? ()
#7  0x000000000196ea9f in ?? ()
#8  0x000000000196ebc7 in ?? ()
#9  0x0000000001929d6a in ?? ()
#10 0x00000000018b7061 in ?? ()
#11 0x00000000018b6d4d in ?? ()
#12 0x00000000014b95c1 in ?? ()
#13 0x00000000014b98c8 in ?? ()
#14 0x0000000001adf60c in ?? ()
#15 0x0000000001ae3258 in ?? ()
#16 0x0000000001af1a2d in ?? ()
#17 0x0000000001a6126c in ?? ()
#18 0x0000000001a786de in ?? ()
#19 0x0000000001678cae in ?? ()
#20 0x0000000001678da0 in ?? ()
#21 0x00000000006dbe52 in ?? ()
#22 0x00007fb76064ca87 in __libc_start_main () from /lib64/libc.so.6
#23 0x000000000077fa7a in ?? ()

@dedmen - any chance to receive debugging symbols or if this is not possible, could you look at the dump?

strace -p PID at the time of crash also not informative:

fstat(4, {st_mode=S_IFREG|0444, st_size=0, ...}) = 0
read(4, "624940 392635 13364 9899 0 59933"..., 1024) = 36
close(4)                                = 0
recvfrom(1861, 0x7ffd333e72c0, 1400, 0, 0x7ffd333e72b0, [16]) = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=1883, events=POLLIN}], 1, 0)  = 0 (Timeout)
futex(0x7f2055fc43f8, FUTEX_WAKE_PRIVATE, 1) = 1
...
...
futex(0x7f20aca1a4c0, FUTEX_WAKE_PRIVATE, 1) = 1
futex(0x7f20aca157f8, FUTEX_WAKE_PRIVATE, 1) = 1
futex(0x2e99960, FUTEX_WAKE_PRIVATE, 1) = 1
openat(AT_FDCWD, "/proc/self/statm", O_RDONLY) = 4
fstat(4, {st_mode=S_IFREG|0444, st_size=0, ...}) = 0
read(4, "624940 392767 13364 9899 0 59933"..., 1024) = 36
close(4)                                = 0
--- SIGSEGV {si_signo=SIGSEGV, si_code=SEGV_MAPERR, si_addr=NULL} ---
+++ killed by SIGSEGV (core dumped) +++

Code which trigger crash:

_target = createVehicle ["CBA_I_InvisibleTarget", [0, 0, 0], [], 0, "NONE"];

Core dump: https://drive.google.com/file/d/1i4TFehaUrxygEUccGzn-mm-NPeJfcVd-/view?usp=sharing

[ToxaBes]

Update: issue related to model https://github.com/CBATeam/CBA_A3/blob/master/addons/ai/InvisibleTarget.p3d

For testing I change this model to \A3\Structures_F\System\ClutterCutter_small_F.p3d and issue gone, but AI don't reveal this model on good level. I think this model issue could be related to new changes in fire geometry or something like that -> https://community.bistudio.com/wiki/Arma_3:_Characters_Firegeometry_Update

[dedmen]

Does anyone have a actual repro case?
Just spawn invisible target thats it?
linux only or windows too?

[TheCandianVendingMachine]

Does anyone have a actual repro case?
Just spawn invisible target thats it?
linux only or windows too?

The annoying thing is that its inconsistent. I've had it working for hours at a time, and then it crashes while sometimes it crashes immediately.

private _targetVehicle = createVehicle ["CBA_B_InvisibleTargetVehicle", [0, 0, 0], [], 0, "NONE"];
private _targetUnit = createAgent ["B_UAV_F", [0, 0, 0], [], 0, "NONE"]; // can also be createUnit

_targetUnit moveInAny _targetVehicle;

this has crashed it in the past, and like I said sometimes it doesn't crash the server and allows me to remove the person inside to avoid a crash

[commy2]

_targetVehicle is undefined?

[TheCandianVendingMachine]

_targetVehicle is undefined?

Fixed, GitHub hid the line for some reason

[freghar]

The most reliable reproducer for me is to use a dedicated server. When placing these units from Curator, it always crashes the server only, rarely (if ever) the client(s).

Does anyone have a actual repro case?
Just spawn invisible target thats it?
linux only or windows too?

Windows dedicated server, windows client, both 64-bit. The server process simply ends with the "process has stopped working" windows dialog.

I have the .bidmp and .mdmp files, but I'm not sure if they contain some sensitive info (steam id, windows account name, etc.), so won't attach them here for now.

The reproducer is really just:

1. start Arma 3 Launcher, select CBA as the only mod, start the game
2. enter Editor, place down any soldier unit, place down Game Master module, set variable name on the soldier unit to something, set Game Master module owner to the same id
3. export the mission as pbo, put it into MPMissions
4. start arma3server_x64.exe with CBA
5. connect to it via "LAN" from the game server browser, log in, select mission, slot in, continue through the map screen into a running game
6. open up the Curator (Zeus) interface, search for "invisible" in the right panel search bar, BLUFOR units
7. place down any of the 3 units
8. a pop-up will interrupt the fullscreen game (if not, you need to alt-tab) informing you that Arma 3 has stopped working
9. confirm with the only button - Close, and the server process window closes too
10. alt-tab back into the fullscreen game, observe connection issues, indicating that, indeed, the server crashed

I can provide more specifics (server.cfg, cmdlines) if the above doesn't reproduce the issue.

[dedmen]

Found the cause.
The model has 0 resolution slots (its invisible afterall)
But for objects to be spottable by AI, they need to have atleast 1 reslod or the server will crash.

And also got a goo repro rate.

Have AI units on the server (in my case dynamic simulation disabled, pretty sure that doesn't matter)
go into Zeus and place invisible target between them. Server instantly crashes.
Important is that the AI units who spot the invisible target, are local to server and simulated on server.