Windows BSOD 0x000000F5 — FLTMGR_FILE_SYSTEM Fix

What Does This Error Mean?

Blue screen 0x000000F5 (FLTMGR_FILE_SYSTEM) means Windows encountered a fatal error in the Filter Manager — the system that lets antivirus, backup, and encryption software intercept file operations. When a file filter driver (like an antivirus real-time scanner) causes an unrecoverable error while intercepting a file read or write, Windows stops to prevent file system corruption. Antivirus or backup software drivers are the most common cause.

Affected Models

Windows 10
Windows 11
Windows 8.1
Windows Server 2016
Windows Server 2019

Common Causes

An antivirus real-time protection driver encountered an error while scanning a file being accessed
A cloud backup or sync driver (like Dropbox, OneDrive, Google Drive) has a filter driver bug triggered by a specific file operation
File encryption software using a filter driver that conflicts with another filter driver on the same system
Multiple filter drivers from different security products running simultaneously and interfering with each other
The Windows Filter Manager itself has corrupted system files after an interrupted update

How to Fix It

Temporarily disable your antivirus real-time protection and see if the crashes stop. If they do, update your antivirus software to the latest version — the vendor has likely already released a fix for this bug.

Do not leave antivirus disabled permanently. Just long enough to confirm it is the cause, then update it.
If you have multiple security products installed (two antivirus programs, a VPN with its own firewall, etc.), uninstall all but one. Multiple filter drivers from competing security products are a known cause of this BSOD.

Windows 10 and 11 come with Windows Defender built in. You generally only need one additional security product, not two or three.
Update all file sync and backup software. Products like Dropbox, OneDrive, Google Drive, and backup utilities all use file system filter drivers. Visit each product's website and install the latest version.

Cloud sync software updates frequently to fix compatibility issues with Windows updates. Running old versions creates conflicts.
Run SFC to repair Windows Filter Manager system files. Open Administrator Command Prompt and run: sfc /scannow — restart after completion.

A corrupted fltmgr.sys file is a less common but possible cause. SFC replaces it with a fresh copy.
Check the Windows Event Viewer for filter driver errors. Search 'Event Viewer' in the Start menu, go to Windows Logs > System, and look for red Error events around the time of each crash. These often name the specific driver.

Event Viewer timestamps match the crash time shown in Reliability Monitor (search 'Reliability Monitor' in Start).

When to Call a Professional

If you cannot stop the crashes by adjusting security software, a technician should analyze the crash dump to identify the specific filter driver. Multiple competing filter drivers are especially tricky to diagnose without tools like WinDbg.

Frequently Asked Questions

What is the Windows Filter Manager?

The Filter Manager (fltmgr.sys) is a Windows component that acts as a middleman between applications and the file system. It lets third-party software — like antivirus, backup, and encryption tools — intercept and inspect file operations without needing to write their own low-level file system code. Think of it like a toll booth on a highway: every file read and write passes through, and filter drivers can inspect or modify the traffic. When one of these filter drivers misbehaves, the toll booth crashes — and since it sits at the core of file access, the whole system goes down.

Can OneDrive or Google Drive cause this BSOD?

Yes. Cloud sync tools install file system filter drivers to monitor which files change so they can be synced to the cloud. If these drivers have a bug — particularly when handling large files, network interruptions, or conflicts with antivirus scanning the same file at the same time — they can cause this crash. Updating these tools to the latest version is usually sufficient to fix it.

How do I see which filter drivers are installed on my PC?

In an Administrator Command Prompt, run: fltmc — and press Enter. This shows all currently loaded file system filter drivers, their altitude (priority order), and their names. Each entry corresponds to a product or driver that is intercepting file operations. You can search the driver name online to find which software installed it.