These issues usually occur because a previous version of the Personal Accelerator was partially uninstalled, leaving behind corrupted registry entries that point to a non-existent PACR.msi file. How to Find or Reinstall PACR.msi
"PACR.msi was not found" when installing Revit/Revit LT 2024
If pacr.msi is running, you can generate a verbose log to see what it does:
Users frequently encounter errors related to this specific MSI during software updates or fresh installations: "PACR.msi not found" pacr.msi
It looks like you’re asking about pacr.msi — but this isn’t a standard or widely known Windows installer file.
The .msi extension means that when you double-click this file—or when it is triggered by another program—Windows launches msiexec.exe (the Windows Installer service) to execute the installation instructions contained inside.
→ Please describe the context (e.g., documentation, error message, uninstall guide). These issues usually occur because a previous version
If you are prompted for this file or your Revit installation is failing because of it, try these steps: PACR Installation issue - Forums, Autodesk
The file is a critical Windows Installer package specifically used for the Personal Accelerator for Revit (PAC) , a background component developed by Autodesk . It is designed to optimize performance and sync speed for teams collaborating on Revit Cloud Worksharing projects, such as those hosted on BIM 360 or Autodesk Construction Cloud. What is the Purpose of PACR.msi?
To avoid pacr.msi and similar mystery installers in the future: → Please describe the context (e
Open the log and look for registry changes (e.g., HKCU\Software\Microsoft\Windows\CurrentVersion\Run ) or file writes to browser folders.
Through user reports and malware analysis forums, pacr.msi has been linked to several specific sources: