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Bug CurrentPage is NULL

Discussion in 'In-Editor Tutorials Packages' started by CaseyHofland, Mar 14, 2023.

  1. CaseyHofland

    CaseyHofland

    Joined:
    Mar 18, 2016
    Posts:
    592
    I'm trying to create a tutorial with the tutorial authoring package. Usually this is a pleasant experience, however today it just won't work right.

    When I press a tutorial from my tutorial container, it should open the first page, but the whole day, no matter what I try, it keeps giving a Null Reference Exception. I have tried with different scriptable objects, reinstalling the tutorial framework, installing different tutorials to see if the problem persists (it does) - nothing works.

    The full stack trace is below but basically: TutorialController.DeInitializeTutorial calls CurrentTutorial.CurrentPage, which throws a null reference exception. I could fix it but then the problem will just persist in other projects I'd imagine. I have added no code of my own yet, I first wanted to write my whole tutorial out. The tutorial I'm switching to has pages assigned: this is not my first tutorial, I know how to set them up.

    This stupid grmlbrmtlbmr bug has unfortunately ruined all my productivity for the day and I can't continue until it is fixed. I welcome any advice as to how to approach this issue.

    Full Error.png

    Unity 2022.2.2
    Tutorial Framework 3.1.3
    (likely irrelevant) Tutorial Authoring Tools 1.2.2
     
  2. CaseyHofland

    CaseyHofland

    Joined:
    Mar 18, 2016
    Posts:
    592
    I was creating the tutorial on a separate branch on our project, but making it in an entirely different project sidesteps the issue. It's not a great solution, but it works.

    Edit:
    Nevermind, it broke on this new project as well.

    Is there a github where I can create PRs?
     
    Last edited: Mar 16, 2023
  3. Ali-Unity3D

    Ali-Unity3D

    Unity Technologies

    Joined:
    Mar 8, 2021
    Posts:
    23
    The project is not developed in public GitHub but you should be able to open a bug report using the regular Unity bug tracker and it should make its way to the current maintainers of the packages.
     
  4. MostHated

    MostHated

    Joined:
    Nov 29, 2015
    Posts:
    1,227
    Did you ever get this figured out? I was making good headway on a tutorial when I now am getting this as well. It seems to have started as soon as I right-clicked on one of my TutorialPages and hit the Properties option to open it in a floating window so I didn't have to try and keep going back and forth between inspectors. Ever since I did that, I am getting the same TutorialController null reference exception.

    No amount of editor restarts, reimporting of the package, etc, seems to fix it.

    If there is no clear resolution, I will probably just see if I can make a copy of the package for the time being and fix it locally so I can at least continue on.

    --- Edit
    I got it working again by making it a local package, then adding additional checks in each place there ended up being an error. This was the final one I got to in which it let me reset the status of the tutorials and the whole thing started working again.

    I have pages with no Paragraphs because for some steps in my tutorial I create a new blank page and hijack the rootVisualElement using the 'Shown' events and add my own elements. There are no error checks in a number of places in which there probably should.

    Code (CSharp):
    1. // TutorialPage.cs
    2. internal void ResetUserProgressAndCompletionCriteria()
    3. {
    4.     // Added the following check
    5.     if (Paragraphs == null || Paragraphs.Count == 0) { return; }
    6.  
    7.     foreach (var paragraph in Paragraphs)
    8.     {
    9.         if (paragraph.Type != ParagraphType.Instruction) { continue; }
    10.         foreach (var criterion in paragraph.Criteria)
    11.         {
    12.             if (criterion != null && criterion.Criterion != null)
    13.             {
    14.                 criterion.Criterion.Completed.RemoveAllListeners();
    15.                 criterion.Criterion.Invalidated.RemoveAllListeners();
    16.                 criterion.Criterion.StopTesting();
    17.                 criterion.Criterion.ResetCompletionState();
    18.             }
    19.         }
    20.     }
    21.  
    22.     HasMovedToNextPage = false;
    23. }
    24.  
    Then I also added the following, as I didn't realize that I had deleted a TutorialPage to use a different type and it left a blank entry in that sections main tutorial asset.

    Code (CSharp):
    1. // Tutorial.cs      
    2. internal void RaisePageInitiated(TutorialPage page, int index)
    3. {
    4.     // Added the following check
    5.     if (!page)
    6.     {
    7.         Debug.LogError("TutorialPage is null. Check the Tutorial asset.");
    8. #if UNITY_EDITOR
    9.         EditorGUIUtility.PingObject(this);
    10. #endif
    11.         return;
    12.     }
    13.  
    14.     page.Initiate();
    15.     PageInitiated?.Invoke(this, page, index);
    16. }
    17.  
    18.  
    Hopefully if anyone else comes across this issue, it might help.
     
    Last edited: Jun 26, 2023
    CaseyHofland likes this.
  5. CaseyHofland

    CaseyHofland

    Joined:
    Mar 18, 2016
    Posts:
    592
    I wish we could just contribute for this very reason.
    Here’s a nice tip:
    Code (CSharp):
    1. // change this:
    2.         Debug.LogError("TutorialPage is null. Check the Tutorial asset.");
    3.         #if UNITY_EDITOR
    4.         EditorGUIUtility.PingObject(this);
    5.         #endif
    6.  
    7. // to this:
    8.         Debug.LogError("TutorialPage is null. Check the Tutorial asset.", this);
    9.  
    This makes it so the object gets pinged once you click on the error in the console and more closely follows Unity standards.
     
  6. MostHated

    MostHated

    Joined:
    Nov 29, 2015
    Posts:
    1,227
    Yeah, good call. You are definitely right. I was just in a rush to get it figured out so I could keep at it and not lose steam, lol.