Empty error and error in class that was running

Ok, I'm asking because I'm very tired of searching for solutions, make editions and get more and more errors.

My game was working. Everything was fine (yes, I have backups and can restore it).I made a beta version and some people tested it. Worked like a charm. Them I started to make some changes to publish in into some game websites. To make the things easier and don't have to have specific copies for each website, I started to use conditional compilers.

Note: the API for Gamejolt was imported before it into the project, and the standalone was built, tested, no errors.

I wanted to use [Conditional("CONDITION")] to especify if the method can be executed. In some cases I will use #if too, but conditional is more "elegant" to me.

So, I put the smcs.rsp in the /Assets/ with the following:

 -define: GAMEJOLT

So, to use [Conditional] I need to specify System.Diagnostics

Them the Debug isn't exist anymore (unknow error). So I need to use using Debug = UnityEngine.Debug; to correct the thing. The start of the code is now:

        using UnityEngine;
         using System.Collections;
         using System.Diagnostics;
         using Debug = UnityEngine.Debug;
         
         
         public class LogoScreen : MonoBehaviour {
         
             bool autoPlayAnim = false;
             private Animator animator;
 
     .... [the middle of the thing, not changed from the functional version]
 
     [Conditional("GAMEJOLT")]
     void LoginToGameJolt(){
 
         Debug.Log("Here the login for gamejolt");
 
     }
 

Debug exist again. But I get the empty error in the console. The red symbol of "you are doomed" and nothing more. A search (long one) on Google and "it caused by type mismatch between the filename of the script and the class name".

In my case it wasn't. The two class that now are saying "No MonoBehavior scripts in the file, or their name do not match the file name." I don't have changed those classes, they was working before even with this alert.

The code of the class:

   /* Script: Utilities.cs
      * 
      * Library with utility functions
      * 
      */
     using UnityEngine;
     using System.Collections;
     
     public class Utilities {
     
         //Get a color in the three colors gradient 
         //that match the percent
         public Color GetColorHealth(float percent){
     
             Gradient g;
             GradientColorKey[] gck;
             GradientAlphaKey[] gak;
     
 .... [the rest of the thing]
 

My game was working before I tried only to use Conditional. And now any new script that I try to create in Unity, using Create->C# Script gives me the same error, even with MonoBehavior and name is ok. But only in this project. Other projects that doesn't have the Conditional is working.

Then I ripped off all the code that use the conditional (only one class), deleted the rmcs.rsp and no way to get the things working back. I even tried to Reimport All.

The backup is working, the version with the changes, no way to work again.

There is something that I'm missing?

(I worked with a lot of languages and frameworks in my life, even becoming a collaborator in an Access & VB magazine long time ago after resolving a crazy weird stupid problem. Now, no way, Unity is winning the fight for now :P )