[Baltazar]

Here is an example source code I've just made. It gives the same error:

Код:

#include ".\SDK\plugin.h"
#include ".\sampgdk\sampgdk.h"

//
extern void * pAMXFunctions;

//
typedef void (*logprintf_t)(char* format, ...);
logprintf_t logprintf;

cell AMX_NATIVE_CALL test(AMX * amx, cell * params){
  char test[] = "test message";
  SendClientMessage(params[1], 0xFFFFFFFF, test);

  return 0;
}

AMX_NATIVE_INFO PluginNatives[] = {
  {"test", test},
  {0, 0}
};

PLUGIN_EXPORT unsigned int PLUGIN_CALL Supports(){

  return sampgdk::Supports() | SUPPORTS_VERSION | SUPPORTS_AMX_NATIVES | SUPPORTS_PROCESS_TICK;
}

PLUGIN_EXPORT bool PLUGIN_CALL Load(void **ppData){
  pAMXFunctions = ppData[PLUGIN_DATA_AMX_EXPORTS];
  logprintf = (logprintf_t)ppData[PLUGIN_DATA_LOGPRINTF];

  return sampgdk::Load(ppData);
}

PLUGIN_EXPORT void PLUGIN_CALL Unload(){
  sampgdk::Unload();
}

PLUGIN_EXPORT int PLUGIN_CALL AmxLoad(AMX *amx){

  return amx_Register(amx, PluginNatives, -1);
}


PLUGIN_EXPORT int PLUGIN_CALL AmxUnload(AMX *amx){

  return AMX_ERR_NONE;
}

PLUGIN_EXPORT void PLUGIN_CALL ProcessTick(){
  sampgdk::ProcessTick();
}

http://s27.postimg.org/pkclb06iq/example_plugin.jpg

Using project settings:
SAMPGDK_AMALGAMATION is globally defined
.def file is defined
additional include directories defined