[Bug]: Failed to Initialize the add-in

[rbunns]

✈ 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

Had PyRevit installed when Revit 2023 was released, got it working (I don't remember the version). Went to update and installed latest version 5.0.1 to get onto Revit 2025. However came got the error Failed to Initialize the add-in "PyrevitLoader" because assembly pyRevitLoader.dll does not exist. Went to file location and am not seeing that file extension. Saw through previous to check via cmd if pyrevit was installed. Admittedly out of my area but looks like it did install?

The firm I work with does utilize SentinielOne but had established the necessary steps to allow Pyrevit to run on my system. Unsure if updating requires to go through those steps again.

⌨ Error/Debug Message

Failed to Initialize the add-in "PyRevitLoader" because the assembly "C:\ProgramFile\pyrevit-Master\bin\n...\pyRevitLoade.dll" does not exist

♻️ To Reproduce

No response

⏲️ Expected behavior

No response

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

Microsoft Windows [Version 10.0.22631.4890]
(c) Microsoft Corporation. All rights reserved.

U:\>pyrevit env
==> Registered Clones (full git repos)
==> Registered Clones (deployed from archive/image)
master | Deploy: "basepublic" | Branch: "master" | Version: "4.8.12.22247+0031" | Path: "C:\Program Files\pyRevit-Master"
==> Attachments
master | Product: "Autodesk Revit 2025" | Engine: ? | Path: "C:\Program Files\pyRevit-Master"
master | Product: "Autodesk Revit 2024" | Engine: ? | Path: "C:\Program Files\pyRevit-Master"
master | Product: "Autodesk Revit 2023" | Engine: ? | Path: "C:\Program Files\pyRevit-Master"
master | Product: "Autodesk Revit 2022" | Engine: ? | Path: "C:\Program Files\pyRevit-Master"
master | Product: "Autodesk Revit 2021" | Engine: ? | Path: "C:\Program Files\pyRevit-Master"
master | Product: "2020.2.1 (New Install)" | Engine: ? | Path: "C:\Program Files\pyRevit-Master"
master | Product: "2019.2 (Full Install)" | Engine: ? | Path: "C:\Program Files\pyRevit-Master"
==> Installed Extensions
==> Default Extension Search Path
C:\Users\rbunnell\AppData\Roaming\pyRevit\Extensions
==> Extension Search Paths
==> Extension Sources - Default
https://github.com/eirannejad/pyRevit/raw/master/extensions/extensions.json
==> Extension Sources - Additional
==> Installed Revits
Autodesk Revit 2025 | Version: 25.2.0.38 | Build: 20240715_1515(x64) | Language: 1033 | Path: "C:\Program Files\Autodesk\Revit 2025\"
Autodesk Revit 2024 | Version: 24.2.0.63 | Build: 20231029_1515(x64) | Language: 1033 | Path: "C:\Program Files\Autodesk\Revit 2024\"
Autodesk Revit 2023 | Version: 23.0.11.19 | Build: 20220503_1030(x64) | Language: 1033 | Path: "C:\Program Files\Autodesk\Revit 2023\"
Autodesk Revit 2022 | Version: 22.1.30.34 | Build: 20220520_1515(x64) | Language: 1033 | Path: "C:\Program Files\Autodesk\Revit 2022\"
Autodesk Revit 2021 | Version: 21.1.21.45 | Build: 20201116_1100(x64) | Language: 1033 | Path: "C:\Program Files\Autodesk\Revit 2021\"
2020.2.1 (New Install) | Version: 20.2.12.1 | Build: 20200210_1400(x64) | Language: 1033 | Path: "C:\Program Files\Autodesk\Revit 2020\"
2019.2 (Full Install) | Version: 19.2.1.1 | Build: 20190108_1515(x64) | Language: 1033 | Path: "C:\Program Files\Autodesk\Revit 2019\"
==> Running Revit Instances
Error: Object reference not set to an instance of an object.
Run with "--debug" option to see debug messages

Additional context

[jmcouffin]

The version you have installed on your computer is extremely old.
We can't support backward, not a big enough team.
You need to follow https://pyrevitlabs.notion.site/Installation-issues-f6495adb56254e9e8021f8a68e3b2ab7
it solves most issues 99% of the time.
Basically, uninstall old version -> install latest release

[rbunns]

That worked thanks! Apologies I had assumed that installing the newer version would have overwritten the older version! Is that the case for any updated version? Uninstall old and reinstall new? Want to make sure I have the correct information to relay to my team.

[jmcouffin]

Uninstall old and reinstall new

yes it is always the way to go.