[Bug]: C# Script

[CuongGIK]

✈ Pre-Flight checks

• I don't have SentinelOne antivirus installed (see above for the solution)
• I have searched in the issues (open and closed) but couldn't find a similar issue
• I have searched in the pyRevit Forum for similar issues
• I already followed the installation troubleshooting guide thoroughly
• I am using the latest pyRevit Version

🐞 Describe the bug

pyRevit 6.0 cannot run C#? Even though previously it worked well with version 5.3

⌨ Error/Debug Message

[Window Title]
Command Failure for External Command

[Main Instruction]
Revit could not complete the external command. Contact the provider for assistance.  Information they provided to Revit about their identity: .

[Expanded Information]
Revit encountered a Non-ASCII character '\xe1' in file C:\Portal Apps\pyGIKTools\GIK.extension\pyGIK.tab\Dev.panel\Test_CS.pushbutton\script.cs on line 16, but no encoding declared; see http://www.python.org/peps/pep-0263.html for details

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♻️ To Reproduce

No response

⏲️ Expected behavior

No response

🖥️ Hardware and Software Setup (please complete the following information)

==> Registered Clones (full git repos)
==> Registered Clones (deployed from archive/image)
master | Branch: "master" | Version: "6.0.0.26032+2145" | Path: "C:\Program Files\pyRevit-Master"
==> Attachments
master | Product: "2026 First Customer Ship" | Engine: DEFAULT (2712) | Path: "C:\Program Files\pyRevit-Master" | AllUsers
master | Product: "2025 First Customer Ship" | Engine: DEFAULT (2712) | Path: "C:\Program Files\pyRevit-Master" | AllUsers
master | Product: "2024.3.4" | Engine: DEFAULT (2712) | Path: "C:\Program Files\pyRevit-Master" | AllUsers
==> Installed Extensions
==> Default Extension Search Path
C:\Users\CuongGIK\AppData\Roaming\pyRevit\Extensions
==> Extension Search Paths
==> Extension Sources - Default
https://github.com/pyrevitlabs/pyRevit/raw/master/extensions/extensions.json
==> Extension Sources - Additional
==> Installed Revits
2026 First Customer Ship | Version: 26.0.4.409 | Build: 20250227_1515(x64) | Language: 1033 | Path: "C:\Program Files\Autodesk\Revit 2026\"
2025 First Customer Ship | Version: 25.0.2.419 | Build: 20240307_1300(x64) | Language: 1033 | Path: "C:\Program Files\Autodesk\Revit 2025\"
2024.3.4 | Version: 24.3.40.26 | Build: 20250918_1515(x64) | Language: 1033 | Path: "C:\Program Files\Autodesk\Revit 2024\"
==> Running Revit Instances
Error: Object reference not set to an instance of an object.
Run with "--debug" option to see debug messages

Additional context

No response

[nasmovk]

I have this same problem. A script.cs that worked before, now does not run and gives a "IronPython Traceback:" error in the output.

[romangolev]

Hi @CuongGIK, @nasmovk, thanks for opening an issue.

The C# scripts execution is surely supported. The matter of fact that with the new loader it bypasses IronPython and fully relies on a new Parser module, Roslyn emitter and lastly .NET reflection to execute the script. So basically it shouldn't even return any "IronPython Traceback".

Can you make sure that you are using the new loader? In pyRevit.ini the following property should be set as follows:
new_loader = true

Please, double check that, wipe out all cache from AppData\Roaming\pyRevit\202x, try again and let me know if the issue persist

[CuongGIK]

Hi @romangolev
I deleted everything in C:\Users\username\AppData\Roaming\pyRevit and uninstalled pyRevit and reinstalled it
I checked pyRevit_config.ini
The result is still an error.
Please see the attached image and code

Test_CS.pushbutton.zip

[nasmovk]

Hi. @romangolev
Thanks for your help.
I have done what you suggest, but my .cs is still showing the IronPython Traceback.
I do see "Could not load file or assembly 'System.Management" in CLI pyrevit env
Strangely the env also shows Windows 10, but it is actually Windows 11.

PS C:\Users\k> pyrevit env

==> Registered Clones (full git repos)
==> Registered Clones (deployed from archive/image)
master | Branch: "master" | Version: "6.0.0.26032+2145" | Path: "C:\Program Files\pyRevit-Master"
==> Attachments
master | Product: "2026 First Customer Ship" | Engine: DEFAULT (2712) | Path: "C:\Program Files\pyRevit-Master"
master | Product: "2025 First Customer Ship" | Engine: DEFAULT (2712) | Path: "C:\Program Files\pyRevit-Master"
master | Product: "2024.3.3" | Engine: DEFAULT (2712) | Path: "C:\Program Files\pyRevit-Master"
master | Product: "2023.1.6" | Engine: DEFAULT (2712) | Path: "C:\Program Files\pyRevit-Master"
master | Product: "2022.1.7" | Engine: DEFAULT (2712) | Path: "C:\Program Files\pyRevit-Master"
==> Installed Extensions
==> Default Extension Search Path
C:\Users\ddd\AppData\Roaming\pyRevit\Extensions
==> Extension Search Paths
==> Extension Sources - Default
https://github.com/pyrevitlabs/pyRevit/raw/master/extensions/extensions.json
==> Extension Sources - Additional
==> Installed Revits
2026 First Customer Ship | Version: 26.0.4.409 | Build: 20250227_1515(x64) | Language: 1033 | Path: "C:\Program Files\Autodesk\Revit 2026\"
2025 First Customer Ship | Version: 25.0.2.419 | Build: 20240307_1300(x64) | Language: 1033 | Path: "C:\Program Files\Autodesk\Revit 2025\"
2024.3.3 | Version: 24.3.30.11 | Build: 20250516_1515(x64) | Language: 1033 | Path: "C:\Program Files\Autodesk\Revit 2024\"
2023.1.6 | Version: 23.1.60.36 | Build: 20241107_1515(x64) | Language: 1033 | Path: "C:\Program Files\Autodesk\Revit 2023\"
2022.1.7 | Version: 22.1.70.9 | Build: 20240704_1515(x64) | Language: 1033 | Path: "C:\Program Files\Autodesk\Revit 2022\"
==> Running Revit Instances
PID: 37872 | 2026.4 | Version: 26.4.0.32 | Build: 20251103_1515(x64) | Language: 0 | Path: "C:\Program Files\Autodesk\Revit 2026"
==> User Environment
Microsoft Windows 10 [Version 10.0.26200]
Executing User: q\k
Error: Could not load file or assembly 'System.Management, Version=8.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'. Le fichier spécifié est introuvable.
Run with "--debug" option to see debug messages

[jmcouffin]

Can you run pyrevit env --debug @nasmovk ?

[jmcouffin]

got it, and deleted right after, not so secret ;p

[jmcouffin]

Please provide the CS scripts @CuongGIK and @nasmovk

the error is a encoding error where you have an accent in your strings (like in french ;) àéèê) and your encoding is not declared properly or text not encoded or decoded properly.

I will close the issue until you provide a proper sample script

[nasmovk]

For info, I did not have any French etc character in my CS script.
The problem has now disappeared after installing the 6.1 release.
I guess you can keep the issue closed.

Below is my CS script, if you happen to be interested :

using System;
using System.Collections.Generic;
using System.Linq;
using System.IO;
using Autodesk.Revit.DB;
using Autodesk.Revit.UI;
using Autodesk.Revit.ApplicationServices;
using Autodesk.Revit.Attributes;


// File-scoped namespace (C# 10+)
namespace MyProject.Modules;

public class DocumentProperties(Document doc)
{
    public Document Document { get; set; } = doc;
    public List<ElementId> ViewIds { get; set; } = new();
    public List<UIView> UIViews { get; set; } = new();
    public List<ElementId> ShowableElementIds { get; set; } = new();
}

[Transaction(TransactionMode.Manual)]
public class TidyTabsCommand : IExternalCommand
{
    public Result Execute(ExternalCommandData commandData, ref string message, ElementSet elements)
    {
        UIApplication uiapp = commandData.Application;
        Application app = uiapp.Application;

        try
        {
            var openDocs = app.Documents.Cast<Document>()
                .Where(d => !d.IsLinked)
                .ToList();

            var docPropList = BuildDocPropList(uiapp, openDocs);
            CloseDocViews(docPropList);

            var usableDocList = docPropList
                .Where(dp => IsDocUseable(dp.Document))
                .ToList();

            ReopenDocViews(uiapp, usableDocList);
        }
        catch (Exception ex)
        {
            message = $"Tidy Tabs Error: {ex.Message}";
            return Result.Failed;
        }

        return Result.Succeeded;
    }

    private List<DocumentProperties> BuildDocPropList(UIApplication uiapp, List<Document> docs)
    {
        List<DocumentProperties> docList = new();
        foreach (Document doc in docs)
        {
            UIDocument uidoc = new(doc);
            DocumentProperties docProps = new(doc);

            foreach (UIView uiview in uidoc.GetOpenUIViews())
            {
                docProps.ViewIds.Add(uiview.ViewId);
                docProps.UIViews.Add(uiview);

                var showableElement = new FilteredElementCollector(doc, uiview.ViewId)
                    .WhereElementIsNotElementType()
                    .FirstOrDefault(e => e.GetTypeId() != ElementId.InvalidElementId && 
                                       (e.Category == null || e.Category.Id.IntegerValue != (int)BuiltInCategory.OST_Cameras));
                
                docProps.ShowableElementIds.Add(showableElement?.Id);
            }
            docList.Add(docProps);
        }
        return docList;
    }

    private void CloseDocViews(List<DocumentProperties> docList)
    {
        foreach (var dp in docList)
        {
            // Close all but the primary tab
            for (int i = 1; i < dp.UIViews.Count; i++)
            {
                dp.UIViews[i].Close();
            }
        }
    }

    private bool IsDocUseable(Document doc) => !string.IsNullOrEmpty(doc.PathName) && !doc.IsDetached;

    private void ReopenDocViews(UIApplication uiapp, List<DocumentProperties> usableDocList)
    {
        foreach (var dp in usableDocList)
        {
            Document doc = dp.Document;
            UIDocument uidoc = null;

            if (File.Exists(doc.PathName))
                uidoc = uiapp.OpenAndActivateDocument(doc.PathName);
            else if (doc.IsModelInCloud)
                uidoc = uiapp.OpenAndActivateDocument(doc.GetCloudModelPath(), new OpenOptions(), false);

            if (uidoc != null)
            {
                for (int i = 0; i < dp.ViewIds.Count; i++)
                {
                    if (doc.GetElement(dp.ViewIds[i]) is View view)
                    {
                        uidoc.ActiveView = view;
                        if (dp.ShowableElementIds[i] is ElementId id)
                        {
                            uidoc.ShowElements(id);
                        }
                    }
                }
            }
        }
    }
}`