[Bug]: Error loading PyRevit in only Revit 2024

[ntoyisea]

✈ 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

Revit 2024 gives an error when opening about pyrevit. I tried following the steps on forum with IT but didnt work.

⌨ Error/Debug Message

Failed to initialize the add-in "PyRevitLoader" because an application already exists with this AddInId node. The AddInId node is a Globally Unique Identifier (GUID) upsend to identify the add-in application. Revit already has an application registered with the indicated GUID

♻️ To Reproduce

No response

⏲️ Expected behavior

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

C:\Users\athenkosi.ntoyise>pyrevit env
==> Registered Clones (full git repos)
Error: Could not load file or assembly 'MadMilkman.Ini, Version=1.0.6.0, Culture=neutral, PublicKeyToken=4e0b5157a7ffbb74' or one of its dependencies. The system cannot find the file specified.
Run with "--debug" option to see debug messages

Additional context

No response

[jmcouffin]

What is the version of pyRevit that you are using?
It looks like you are using an old one.

[ntoyisea]

What is the version of pyRevit that you are using? It looks like you are using an old one.

Thank you. I immediately updated my pyrevit but now a new error comes up

[jmcouffin]

I doubt you uninstalled properly before installing. I still see old references and old issues

In general, you need to uninstall pyrevit before installing a new version.

Please follow https://pyrevitlabs.notion.site/Installation-issues-f6495adb56254e9e8021f8a68e3b2ab7

[duckmiester]

I can confirm we are receiving the same issue in Revit 2024 all of a sudden. Has been working fine for ages, but now throwing this error.

[Window Title]
PyRevitLoader - Error Loading pyRevit

[Main Instruction]
IronPython Traceback:
Traceback (most recent call last):
File "C:\Program Files\pyRevit-Master\bin\engines\pyRevitLoader.py", line 30, in
File "C:\Program Files\pyRevit-Master\pyrevitlib\pyrevit\loader\sessionmgr.py", line 24, in
File "C:\Program Files\pyRevit-Master\pyrevitlib\pyrevit\loader\sessioninfo.py", line 14, in
File "C:\Program Files\pyRevit-Master\pyrevitlib\pyrevit\runtime_init_.py", line 502, in
File "C:\Program Files\pyRevit-Master\pyrevitlib\pyrevit\runtime_init_.py", line 344, in get_runtime_asm
File "C:\Program Files\pyRevit-Master\pyrevitlib\pyrevit\runtime_init.py", line 295, in _generate_runtime_asm
AttributeError: Method not found: 'System.Collections.Immutable.ImmutableArray`1 System.Reflection.Metadata.MetadataReader.GetBlobContent(System.Reflection.Metadata.BlobHandle)'.

Script Executor Traceback:
System.MissingMethodException: Method not found: 'System.Collections.Immutable.ImmutableArray1<Byte> System.Reflection.Metadata.MetadataReader.GetBlobContent(System.Reflection.Metadata.BlobHandle)'. at Microsoft.Scripting.Runtime.LightExceptions.ThrowException(LightException lightEx) at Microsoft.Scripting.Runtime.LightExceptions.CheckAndThrow(Object value) at Microsoft.Scripting.Interpreter.FuncCallInstruction2.Run(InterpretedFrame frame)
at Microsoft.Scripting.Interpreter.Interpreter.HandleException(InterpretedFrame frame, Exception exception)
at Microsoft.Scripting.Interpreter.Interpreter.Run(InterpretedFrame frame)
at Microsoft.Scripting.Interpreter.LightLambda.Run1[T0,TRet](T0 arg0)
at IronPython.Compiler.Ast.CallExpression.Invoke0Instruction.Run(InterpretedFrame frame)
at Microsoft.Scripting.Interpreter.Interpreter.Run(InterpretedFrame frame)
at Microsoft.Scripting.Interpreter.LightLambda.Run1[T0,TRet](T0 arg0)
at System.Dynamic.UpdateDelegates.UpdateAndExecute2[T0,T1,TRet](CallSite site, T0 arg0, T1 arg1)
at IronPython.Compiler.Ast.CallExpression.Invoke0Instruction.Run(InterpretedFrame frame)
at Microsoft.Scripting.Interpreter.Interpreter.Run(InterpretedFrame frame)
at Microsoft.Scripting.Interpreter.LightLambda.Run1[T0,TRet](T0 arg0)
at IronPython.Compiler.RuntimeScriptCode.InvokeTarget(Scope scope)
at IronPython.Runtime.PythonContext.InitializeModule(String fileName, ModuleContext moduleContext, ScriptCode scriptCode, ModuleOptions options)
at IronPython.Runtime.Importer.LoadModuleFromSource(CodeContext context, String name, String path)
at IronPython.Runtime.Importer.LoadFromDisk(CodeContext context, String name, String fullName, String str)
at IronPython.Runtime.Importer.ImportFromPathHook(CodeContext context, String name, String fullName, List path, Func5 defaultLoader) at IronPython.Runtime.Importer.ImportFromPath(CodeContext context, String name, String fullName, List path) at IronPython.Runtime.Importer.ImportNestedModule(CodeContext context, PythonModule module, String[] parts, Int32 current, List path) at IronPython.Runtime.Importer.ImportFrom(CodeContext context, Object from, String name) at IronPython.Modules.Builtin.__import__(CodeContext context, String name, Object globals, Object locals, Object fromlist, Int32 level) at IronPython.Runtime.Importer.ImportLightThrow(CodeContext context, String fullName, PythonTuple from, Int32 level) at Microsoft.Scripting.Interpreter.FuncCallInstruction5.Run(InterpretedFrame frame)
at Microsoft.Scripting.Interpreter.Interpreter.Run(InterpretedFrame frame)
at Microsoft.Scripting.Interpreter.LightLambda.Run1[T0,TRet](T0 arg0)
at IronPython.Compiler.RuntimeScriptCode.InvokeTarget(Scope scope)
at IronPython.Runtime.PythonContext.InitializeModule(String fileName, ModuleContext moduleContext, ScriptCode scriptCode, ModuleOptions options)
at IronPython.Runtime.Importer.LoadModuleFromSource(CodeContext context, String name, String path)
at IronPython.Runtime.Importer.LoadFromDisk(Cod

[jmcouffin]

@duckmiester do you mean you did not play with pyrevit installs and the errors just popped? (After an update of Revit at least)

Please report the output from running pyrevit env command in cli

[duckmiester]

@jmcouffin yep correct. Out of the blue! Led me down a rabbit hole of completely uninstalling / reinstalling to no avail.

pyrevit env results below

C:\WINDOWS\system32>pyrevit env
==> Registered Clones (full git repos)
==> Registered Clones (deployed from archive/image)
master | Deploy: "basepublic" | Branch: "master" | Version: "4.8.16.24121+2117" | Path: "C:\Program Files\pyRevit-Master"
==> Attachments
master | Product: "Autodesk Revit 2025" | Engine: DEFAULT (2711) | Path: "C:\Program Files\pyRevit-Master" | AllUsers
master | Product: "Autodesk Revit 2024" | Engine: DEFAULT (2711) | Path: "C:\Program Files\pyRevit-Master" | AllUsers
master | Product: "Autodesk Revit 2023" | Engine: DEFAULT (2711) | Path: "C:\Program Files\pyRevit-Master" | AllUsers
master | Product: "Autodesk Revit 2022" | Engine: DEFAULT (2711) | Path: "C:\Program Files\pyRevit-Master" | AllUsers
master | Product: "2021.1.9" | Engine: DEFAULT (2711) | Path: "C:\Program Files\pyRevit-Master" | AllUsers
master | Product: "2020.2.9" | Engine: DEFAULT (2711) | Path: "C:\Program Files\pyRevit-Master" | AllUsers
==> Installed Extensions
==> Default Extension Search Path
C:\WINDOWS\system32\config\systemprofile\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
Autodesk Revit 2025 | Version: 25.0.2.419 | Build: 20240307_1300(x64) | Language: 1033 | Path: "C:\Program Files\Autodesk\Revit 2025"
Autodesk Revit 2024 | Version: 24.3.10.22 | Build: 20241105_1515(x64) | Language: 1033 | Path: "C:\Program Files\Autodesk\Revit 2024"
Autodesk Revit 2023 | Version: 23.1.60.36 | Build: 20241107_1515(x64) | Language: 1033 | Path: "C:\Program Files\Autodesk\Revit 2023"
Autodesk Revit 2022 | Version: 22.1.80.32 | Build: 20241107_1515(x64) | Language: 1033 | Path: "C:\Program Files\Autodesk\Revit 2022"
2021.1.9 | Version: 21.1.90.15 | Build: 20230907_1515(x64) | Language: 1033 | Path: "C:\Program Files\Autodesk\Revit 2021"
2020.2.9 | Version: 20.2.90.12 | Build: 20220517_1515(x64) | Language: 1033 | Path: "C:\Program Files\Autodesk\Revit 2020"
==> Running Revit Instances
Error: Object reference not set to an instance of an object.
Run with "--debug" option to see debug messages

[jmcouffin]

Please uninstall old version and download WIP installers from the actions tab or from the https://pyrevitlabs.io website using the orange button and report.

[ntoyisea]

I doubt you uninstalled properly before installing. I still see old references and old issues

In general, you need to uninstall pyrevit before installing a new version.

Please follow https://pyrevitlabs.notion.site/Installation-issues-f6495adb56254e9e8021f8a68e3b2ab7

It worked. Thanks