Invalid packet, gamebase unpackUpdate

#1 Have you changed the onAdd(), onNewDataBlock(), or unpack/packUpdate functions for any objects you are using? When did this behavior start happening? Can you give us some more background info?

#2 I have 3 new object types.

1) pretty much copied directly from the simple conobject example. it's never updated and i'm pretty sure that's not the problem.

the other 2 are much more likely subjects:

2) I am porting from another engine, in which my game was based on a global game object. I have made it derive from a gamebase object so that it receives tick updates. It doesn't change the onadd, onnewdatablock, or pack/unpack. however, because of how my game was written, I instantiated this object in a funny way:

CreatrixGame CG;
CreatrixGameData CGD;  

void CreatrixGame::Init()
{
	setDataBlock (&CGD);
	registerObject("CG");
}

3) My game objects are also derived from GameBase. For them, I took the Item.cc code almost verbatim and changed only the things I needed. I did make a few changes to the unpack/pack update for these objects, but not to the unpack/pack data, onAdd or onNewDataBlock.

NOTE: I am especially interested in general methods used for debugging this type of problem. Not necessarily an answer to this specific crash...

#3 Well, I just had the exact same error recently, although for a different reason. What I did was a text search using Agent Ransack, and found where the error message "invalid packet GameBase::unpackUpdate()" was. Here it is:

void GameBase::unpackUpdate(NetConnection *con, BitStream *stream)
//...
if (!Sim::findObject(id,dptr) || !setDataBlock(dptr))
  con->setLastError("Invalid packet GameBase::unpackUpdate()");
//...

Using the VS.net debugger, I put a breakpoint on the if command, then did a Step Into to see what was going on. The error only occurred when I added my object to the game world, so that's why I didn't have to worry about tracking lots of unpackUpdates for objects.

findObject() was returning true, but it turns out setDataBlock() of my object was returning false. It was because I had it only taking into account what the server did because I didn't realize the client also called that function. Once I made the right changes (the client object returned true from onNewDataBlock()), everything was alright.

For TGE debugging I typically just put breakpoints everywhere and watch how the variables change. :) After understanding the engine better, things get quicker.

#4 I have been meaning to do a tutorial on debugging network stuff, maybe I'll do that today.

Short version: compile with DEBUG_NET enabled, first off, then run it and look for pack/unpack mismatch errors.

#5 Ha! thanks pat, i just discovered that in the code and am working off the clues it's giving me!

#6 Thanks guys i found the bug ;)

looking forward to the network tutorial, pat.

rock on

#7 I get this error also when I added a castle to the game. It turns out that I had forgotten a texture and that caused the problem.