forums.smartfoxserver.com

Hello! I have a log warning with exception and without callstack. How can I track where error came from or maybe fix?

WARN SFSWorker:Sys:3 controllers.v290.SystemReqController java.lang.NullPointerException

Hi,
this is usually caused by the JIT compiler when optimizing code that is invoked very often.
There's a specific setting to get the stack traces back:

-XX:-OmitStackTraceInFastThrow

You can add it to your configuration, via the AdminTool > Server Settings > JVM Settings, then saving and restarting SFS2X.

Hope it helps

Lapo wrote: 20 Nov 2025, 10:46 Hi,
this is usually caused by the JIT compiler when optimizing code that is invoked very often.
There's a specific setting to get the stack traces back:

-XX:-OmitStackTraceInFastThrow

You can add it to your configuration, via the AdminTool > Server Settings > JVM Settings, then saving and restarting SFS2X.

Hope it helps

Thanks, thats really helped with viewing call stack. Further research using decompiler showed that error can be on a server side, addBuddy function, on error handling block.
"throw new SFSBuddyListException("Cannot add Buddy to " + ownerName + " BuddyList. The BuddyList was not loaded first.");" - there is no "errorData" parameter here

Kkkosatkin wrote: 21 Nov 2025, 16:04 "throw new SFSBuddyListException("Cannot add Buddy to " + ownerName + " BuddyList. The BuddyList was not loaded first.");" - there is no "errorData" parameter here

Yes, because there is no server notification sent back to client about this error.
You should catch the issue when you're testing and fix the client by initializing the BuddyList in the LOGIN event, and before allowing users to add buddies to their list.

Cheers

Hello again. I mean, there is an error on server-side code. There is no argument to the error at class constructor, at throwing error exception.

throw new SFSBuddyListException("Cannot add Buddy to " + ownerName + " BuddyList. The BuddyList was not loaded first.") - require "errorData" parameter here. Parent class SFSException constructor set "errorData = null", but the "notifyRequestError" function try to get this value. This error causes "java.lang.NullPointerException" on a log viwer when trying to send error notification. On the client-side, we continue to investigate where the error with desync of buddyList.Inited occured.

Can you provide a step by step description of how to reproduce this?
The details we need are listed here: https://forums.smartfoxserver.com/viewtopic.php?t=16497

Thanks

We haven't fully figured out how this case happens on the client, but we are seeing an error on the server side. On the screenshots 1-2 you can see that when error is thrown (SFSBuddyListException), "errorData" parameter is not used in the constructor, but then this parameter is used (3-rd screenshot)

Yeah... we don't need the decompiled code We know it already. I was asking for a reproducible case.
Thanks anyways.

If you find a way to reproduce the problem please let us know.

Cheers