[SuperViper]

pawn Код:

ShowPlayerDialog(playerid, DIALOG_STYLE_MSGBOX, 19961, "{3333FF}Informatii player",HelpString,"exit", "");

should be changed to

pawn Код:

ShowPlayerDialog(playerid, 19961, DIALOG_STYLE_MSGBOX, "{3333FF}Informatii player",HelpString,"exit", "");

You had the dialog id and the dialog style mixed up.