Minecraft packet 0x2C - Set entity properties

/***
Program output as of folowing code:

Received 0x2c
Setting properties (2) for entity 4d    <---- For some reason, this shows as hex. Also, it's not player entity ID
    generic.movementSpeed = 0.25; (list length:0)
    generic.maxHealth = 10; (list length:0)
Received 0xd3                    <--- this is bullshit. It just means I'm out of sync right here
ERROR: Unknown packet! (0xd3)

---***VARIABLES***---
scl = some class specialised to comunicate with minecraft (read and write variables to stream)


***/

        case 0x2C : {   //Entity properties array
            int entity_id = 0;
            int array_length = 0;
            //Read entity Id and array length
            scl>>entity_id;    //4 bytes read (int)
            scl>>array_length; //4 bytes read (int)

            std::cout<<"Setting properties ("<<(int)array_length<<") for entity "<<(int)entity_id<<'\n';  //Setting properties (2) for entity 4d
            for(int i=0; i<array_length; i++) {
                std::string m_name("");
                double value=0;
                short list_length = -1;  //-1 to make sure that the value was changed
                scl>>m_name;    //2+? bytes read (this displays correct strings like generic.Something)
                scl>>value;     //8 bytes read (values seem to be OK)
                scl>>list_length; //2 bytes - always zero so far
                std::cout<<"    "<<m_name<<" = "<<value<<"; (list length:"<<list_length<<")\n";  //generic.movementSpeed = 0.25; (list length:0)
                if(list_length>0)  //because of -1
                  scl.ignore(list_length*25);  //Ignore them list items, one should be 25 bytes long
            }
        }

/** Whole program output: (not very iseful, just in case you were curious)

Received 0x10
Held item changed to 0
Received 0x4
Received 0x3
[CHAT] [Server] : {"text":"Hello, MXXIV."}
Received 0x3
[CHAT] [Server] : {"text":"The time now is 09:18 (9:18 am) and you\u0027re in wo
rld \u0027world\u0027."}
Received 0x3
[CHAT] [Server] : {"text":"Online (2/20): Darker, MXXIV"}
Received 0x3
[CHAT] [Server] : {"text":"MXXIV joined the game."}
Received 0x17
Received 0x28
Received 0x23
Received 0x17
Received 0x28
Received 0x23
Received 0xc9
Received 0xc9
Received 0xc9
Received 0x3
[CHAT] [Server] : {"text":"Welcome, MXXIV. This is spawn."}
Received 0xd
WARNING: Position corrected! Yaw= 0 Pitch= 0
Received 0x4
Received 0x68
Received 0x67
Received 0x67
Received 0x38
Packet 0x38 received.     <-- receiving chunks
Column X:fffffff7 Z:13 set.
Column X:fffffff8 Z:13 set.
Column X:fffffff8 Z:14 set.
Column X:fffffff7 Z:14 set.
Column X:fffffff6 Z:14 set.
Received 0x18
Received 0x28
Received 0x2c
Setting properties (2) for entity 4d
    generic.movementSpeed = 0.25; (list length:0)
    generic.maxHealth = 10; (list length:0)
Received 0xd3
ERROR: Unknown packet! (0xd3)
*/