An access violation is a Windows-level error that occurs when a process tries to read or write to a memory address it doesn't have permission to access. This can cause Revit to freeze, crash, or display an "Unhandled Exception" dialog. Here's how to troubleshoot it and what to send to support.
What it looks like
A Windows dialog: Revit has encountered an unhandled exception and must close
A dialog mentioning Access Violation or a memory address like
0x00000000Revit freezes completely and must be force-closed from Task Manager
Step 1: Retrieve the Revit journal file first
The Revit journal file contains a precise record of what happened before the crash. Do this before reinstalling or making any changes.
Open File Explorer.
In the address bar, type:
%localappdata%\Autodesk\Revit\Autodesk Revit [your version]\Journals\Sort by Date Modified. The most recent .txt file is the journal from your crashed session.
Copy this file to your desktop — you will send it to Pirros support.
Step 2: Check for plugin conflicts
Access violations often happen when two Revit add-ins load conflicting versions of the same DLL library.
Restart Revit and watch for any startup warning dialogs mentioning add-in failures — note the add-in name.
Go to Add-Ins → External Tools → Manage Add-ins, disable all add-ins except Pirros, restart Revit, and try to reproduce the crash.
If the crash stops, re-enable other add-ins one at a time to find the conflicting one.
Step 3: Reinstall the Pirros plugin
Go to Windows Settings → Apps and uninstall Pirros.
Download the latest installer from your Pirros account dashboard.
Right-click the installer and select Run as administrator.
Restart Revit and test.
What to send to support
If the crash persists after all of the above:
The Revit journal file from the crashed session
Your Revit version and Pirros plugin version
The exact steps that trigger the crash
A list of other Revit add-ins installed on your machine
Your Windows version
See When to contact support (and what info to include) for the full checklist.
FAQ
Q: The crash only happens with one specific Revit file. What does that mean?
A: The issue is likely with the project file itself, not the plugin. That file may contain corrupt elements or families that cause problems when Pirros processes them. Try opening the same file without using the Pirros plugin to check its health first.
Q: Revit crashes during upload, not during insert. Is this the same issue?
A: It can be related. Crashes during upload are often caused by a specific view or element in the model that the plugin cannot process. The journal file from that session is the most useful diagnostic.
Q: After the crash, my Revit file is corrupt. What can I do?
A: Use Revit's built-in recovery: open the file and Revit will offer to open the last auto-saved version. Do not overwrite the corrupt file until you have a working recovery copy. If the file is workshared, Revit may also offer a backup from the central file.