[edon1337]

Enable debug and post the error again, I'll try to fix this.

[F0RCE]

I have debug enable for the whole server (in amxx.cfg)

It is debugged message:

L 02/26/2017 - 13:12:01: Invalid weapon id 0 L 02/26/2017 - 13:12:01: [AMXX] Displaying debug trace (plugin "zp_klasa_szybkostrzelny.amxx") L 02/26/2017 - 13:12:01: [AMXX] Run time error 10: native error (native "get_weaponname") L 02/26/2017 - 13:12:01: [AMXX] [0] zp_klasa_szybkostrzelny.sma::eventCurWeapon (line 45)

[edon1337]

Ok my last guess would be this, also there was a mistake in your code, you need to use || not && at the is_user_alive && zp_core_is_zombie .... Also if you check is_user_alive , is_user_connected is not needed.

/*================================================================================
    
    ----------------------------------
    -*- [ZP] Class: Human: FastShoot -*-
    ----------------------------------
    
    This plugin is part of Zombie Plague Mod and is distributed under the
    terms of the GNU General Public License. Check ZP_ReadMe.txt for details.
    
================================================================================*/


#include <amxmodx>
#include <zp50_class_human>
#include <zp50_core>
#include <engine>
#include <fakemeta>

// Raptor Human Attributes
new const humanclass2_name[] = "Specjalista"
new const humanclass2_info[] = "Szybciej strzela z broni"
new const humanclass2_models[][] = { "leet" }
const humanclass2_health = 75
const Float:humanclass2_speed = 1.0
const Float:humanclass2_gravity = 1.2

new g_HumanClassID

public plugin_init()
{
    register_event("CurWeapon","eventCurWeapon", "b")

}

public eventCurWeapon(id)
{
    new weapon = read_data(2)

    if(!is_user_alive(id) || zp_core_is_zombie(id) || zp_class_human_get_current(id) != g_HumanClassID)
    return PLUGIN_CONTINUE
    
    static Float:fSpeedMultiplier = 0.8;
    
    new szWeaponName[64];
    get_weaponname(weapon, szWeaponName, 63)
    
    new iEnt = find_ent_by_owner(-1, szWeaponName, id)
    
    if(!pev_valid(iEnt))
    return PLUGIN_HANDLED;

    while(iEnt > 0) {
        set_pdata_float( iEnt, 46, ( get_pdata_float(iEnt, 46, 4) * fSpeedMultiplier), 4 );
        set_pdata_float( iEnt, 47, ( get_pdata_float(iEnt, 47, 4) * fSpeedMultiplier), 4 );
    }
    
    return PLUGIN_CONTINUE
}

public plugin_precache()
{
    register_plugin("[ZP] Klasa Ludzi: Specjalista", ZP_VERSION_STRING, "ZP Dev Team")
    
    g_HumanClassID = zp_class_human_register(humanclass2_name, humanclass2_info, humanclass2_health, humanclass2_speed, humanclass2_gravity)
    new index
    for (index = 0; index < sizeof humanclass2_models; index++)
    zp_class_human_register_model(g_HumanClassID, humanclass2_models[index])
}

[F0RCE]

Seems to be working now!
Thank you!