Error when executing schedulable class "no viable alternative at character ' ' "

Question

I'm having an issue executing a schedulable class.

My Schedulable Class:

global class Recordatorio_Cobro implements Schedulable {
    global void execute(SchedulableContext SC) {
        Recordatorio_Cobro_Clase.Recordatorio();
    }
}

My apex class:

public class Recordatorio_Cobro_Clase {
    
    Public static void Recordatorio(){
        List<Account> acct         = [Select Id From Account Where Cliente_Activo__c = TRUE];
        UserRole      RoleAsist    = [SELECT Id from UserRole where Name='Asistente Administrativo'];
        UserRole      RoleAdmin    = [SELECT Id from UserRole where Name='Directora Administrativa'];
        User Asistente             = [Select ID From User Where UserRoleID=:RoleAsist.Id and IsActive = TRUE];
        User Admin                 = [Select ID From User Where UserRoleID=:RoleAdmin.Id and IsActive = TRUE] ;
        list<Opportunity> opp;
        List<Factura__c>  fac_Vencida;
        List<Factura__c>  fac_Abierta;
        
        integer Facturas_Vencidas;
        integer Facturas_Abiertas;
        

        DateTime dia     =   Date.today();
        String num_dia   =   dia.format('u');
       
        
        for (Account acc : acct){
            Facturas_Vencidas = 0;
            Facturas_Abiertas = 0;
            opp = [Select Id From Opportunity Where AccountId =: acc.id];
            for (Opportunity op: opp){
                fac_Vencida = [Select Id, Estado_de_Factura__c From Factura__c Where Estado_de_Factura__c = 'Abierta/Vencida' and Opportunity__c =: op.id];
                fac_Abierta = [Select Id, Estado_de_Factura__c From Factura__c Where Estado_de_Factura__c = 'Abierta' and Opportunity__c =: op.id];
                Facturas_Vencidas  = Facturas_Vencidas + fac_Vencida.size();
                Facturas_Abiertas  = Facturas_Abiertas + fac_Abierta.size();

                
            }
                
            If (Facturas_Vencidas==0 && Facturas_Abiertas>0 && num_dia=='7' ){
                
                    Task t= new task();
                    t.Subject       =   'Cobrar al cliente';
                    t.ActivityDate  =   Date.today();
                    t.Description   =   'Contactar al cliente para recordarle que tiene una factura abierta e intentar cobrarle';
                    t.Status        =   'Open';
                    t.WhatId        =   acc.Id;
                    t.OwnerId       =   Asistente.id;
                    t.Priority      =   'Normal';
                    
                    insert t;
                
            }

            if (Facturas_Vencidas>0){
                
                Task t= new task();
                    t.Subject       =   'Cobrar al cliente';
                    t.ActivityDate  =   Date.today();
                    t.Description   =   'Contactar a cliente MOROSO para cobrarle';
                    t.Status        =   'Open';
                    t.WhatId        =   acc.Id;
                    t.OwnerId       =   Admin.id;
                    t.Priority      =   'Normal';
                    
                    insert t;
            }
        }
    }
}

The command I use in execute anonymous windows:

Recordatorio_Cobro s=new Recordatorio_Cobro();
s.execute(null);

And the error I receive is:

Line: 2, Column: 15

line 2:15 no viable alternative at character ' '

I have searched and can't seem to find the reason for this error. Could someone guide me in the right direction?