PC Slower Than It Used to Be?
A free scan shows the junk files, broken settings and background clutter dragging Windows down - then fixes them in one click.Free scan · Windows 10 & 11Outdated Drivers Are Slowing You Down
One free scan finds every outdated or missing driver and matches the right update for your exact hardware.Free scan · exact hardware matchSome links on this page are affiliate links: if you buy through them we may earn a commission, at no extra cost to you.
Avast Passwords error code 0x8009000BU is usually a sign-in, synchronization, network-access, or Avast application problem rather than a hardware fault. Restart Windows, confirm that DNS and your firewall are not blocking Avast, and turn Passwords sync back on before attempting a reinstall. If those checks do not help, use Avast’s built-in Repair App, then reinstall only from Avast’s official installer page after confirming that your vault is synchronized or otherwise recoverable.
No official Avast page reviewed here decodes this exact code or assigns it to one universal cause. The practical fix is therefore a risk-ordered diagnosis: protect the vault first, then repair connectivity, synchronization, account access, and the application.
As an Amazon Associate I earn from qualifying purchases.
What does Avast Passwords error 0x8009000BU mean?
The code appears when Avast Passwords fails to open on Windows 10 or Windows 11. TheWindowsClub associates it with several possibilities: a conflict with the Windows account, desynchronization between Avast Antivirus and Avast’s servers, restrictions involving Google accounts, a functional problem in the application, DNS trouble, or a firewall restriction. Those are diagnostic possibilities, not a confirmed cause for every installation.
Avast describes Passwords as encrypted storage and autofill software: “Passwords captures, stores in an encrypted storage and automatically fills passwords, credit cards and notes entered by you.” Its product policy also says that, on Windows, Passwords browser extensions are paired with Avast Antivirus. A failure to open can therefore involve the local app, its account session, or the connection needed to synchronize the encrypted vault.
Popular on Amazon
- Spacious Design: Measuring 21.1" wide and 14.1" deep, our lap desk comfortably fits most laptops up to 15.6". Extra room for accessories ensures convenience.
- Enhanced Functionality: Packed with handy features, including a 5x9" precision tracking mouse pad and a built-in phone slot for seamless work or video calls. Plus, enjoy ergonomic support with the integrated cushioned wrist rest.
- Cool Comfort: Enjoy a stable surface with our lap desk's dual bolster cushion, designed for comfort and airflow, keeping your lap cool during extended use.
- Durable Surface: Work with confidence on our lap desk's solid surface, featuring a sleek black carbon color, ensuring optimal air circulation to prevent your laptop from overheating.
- On-the-Go Convenience: With an integrated handle and lightweight design (2.8 lbs), our lap desk is portable for travel or moving around the house, offering flexibility in any space.
TheWindowsClub’s code-specific guidance is useful for the repair sequence, but Avast has not published a code-specific root-cause table in the official pages reviewed. Do not assume that a recent Windows-password change, a Google account, DNS, or the firewall is always responsible; use each as a clue when it matches what changed on your computer.
What should I check before changing Avast settings?
Start with reversible checks. They do not delete vault data and can clear a temporary sign-in or service connection failure.
- Restart Windows. Close open work, choose Start > Power > Restart, and try Avast Passwords again after Windows loads. A restart can clear a stalled Avast process or a temporary account-session problem.
- Confirm that the internet connection works. Open several unrelated, secure websites. If none load, fix the Windows connection before troubleshooting Passwords. If only Avast-related functions fail, continue with the firewall and DNS checks below.
- Check DNS resolution. A DNS filter, incorrect DNS configuration, or security product can prevent Avast from reaching its services even when some websites still open. Temporarily test with the narrowest change available in your network or security software, then restore your normal protection. Do not leave a broad DNS bypass in place as a permanent fix.
- Inspect firewall controls. Make sure Avast Antivirus and its Passwords components are allowed to make outbound connections. If you test by changing a rule, change only the relevant Avast rule, record the original setting, and restore it immediately after the test. Permanently disabling the firewall removes protection and does not identify the underlying fault.
Retry Passwords after each check instead of changing several controls at once. If the error disappears after a network change, keep that change only if you can verify that it is safe and necessary; otherwise return to the original configuration and continue with synchronization or repair. A corporate VPN, filtering DNS service, or managed firewall may require an administrator to review the rule rather than allowing you to disable it yourself.
How do I turn on Passwords sync and resynchronize the vault?
Synchronization is the safest substantive repair because it can restore the server connection without removing the local application. It also gives you a way to recover the vault before any uninstall or reset.
- Open Avast Antivirus.
- Select Privacy in the main navigation.
- Choose Password, then open Settings.
- Select Sync & Backup.
- Click Turn On. Sign in to your Avast account if Avast prompts you.
- Check My synced devices and verify that the current Windows computer appears there.
If the device appears under My synced devices, wait for synchronization to finish before closing Avast or switching accounts. Check the list again after the sync indicator settles. Avoid uninstalling or deleting app data while the vault is the only copy that may still be available locally. If Turn On is unavailable, sign-in fails, or the device never appears, treat the issue as an account or service-connection problem and continue to the account checks and repair steps.
Do not create a second Avast account just to test the feature. A different account can show an empty vault and make it harder to determine which account owns the original synchronized data. Use the email address that was previously associated with Passwords.
Recommended Free Tools
Also popular on Amazon
- 5-in-1 Connectivity: Equipped with a 4K HDMI port, a 5 Gbps USB-C data port, two 5 Gbps USB-A ports, and a USB C 100W PD-IN port. Note: The USB C 100W PD-IN port supports only charging and does not support data transfer devices such as headphones or speakers.
- Powerful Pass-Through Charging: Supports up to 85W pass-through charging so you can power up your laptop while you use the hub. Note: Pass-through charging requires a charger (not included). Note: To achieve full power for iPad, we recommend using a 45W wall charger.
- Transfer Files in Seconds: Move files to and from your laptop at speeds of up to 5 Gbps via the USB-C and USB-A data ports. Note: The USB C 5Gbps Data port does not support video output.
- HD Display: Connect to the HDMI port to stream or mirror content to an external monitor in resolutions of up to 4K@30Hz. Note: The USB-C ports do not support video output.
- What You Get: Anker 332 USB-C Hub (5-in-1), welcome guide, our worry-free 18-month warranty, and friendly customer service.
How do I use Avast’s Repair App without deleting my vault?
Avast’s in-place repair is the next supported step after restart, network checks, and synchronization. It repairs application files and configuration while avoiding the data-loss risk of removing the product outright.
- Open Avast and select Action Menu > Settings.
- Open General > Troubleshooting.
- Choose REPAIR APP.
- Allow the scan and repair operation to finish. If Avast offers Resolve all, select it.
- Restart Windows and test Avast Passwords again.
The labels can vary slightly by Avast release, but the path remains in the application’s General troubleshooting area. If Avast cannot open far enough to reach these controls, use Windows’ installed-program maintenance route: open Control Panel > Programs and Features, select Avast, choose Change or Repair when the Avast Setup window appears, and follow the on-screen prompts. Do not choose an option that removes the product unless you have first confirmed that the vault is synchronized or otherwise recoverable.
Repair is preferable to an immediate reset because it is more reversible and tests whether damaged files or configuration are responsible. It does not prove that the account or network is healthy; if the repaired application still cannot sign in or register the device, return to those branches rather than repeatedly running repair.
What should I do if Repair App does not fix 0x8009000BU?
Move to a clean installation only after protecting the vault. Avast’s official installation-files page lists the Passwords download. Use that page instead of an unofficial mirror so that the installer and its package are supplied by Avast.
Before uninstalling
- Open Privacy > Password > Settings > Sync & Backup and confirm that sync is enabled.
- Verify that this computer is listed under My synced devices.
- Make sure you can sign in to the Avast account that owns the synchronized vault.
- If synchronization cannot be confirmed, stop and contact Avast Support rather than deleting local app data. An unsynchronized local vault may be the only copy of your saved entries.
Reinstalling from the official source
- Download the current Passwords package from Avast’s installation-files page.
- Use Windows’ installed-program controls to remove or modify the existing Avast installation only after the checks above are complete.
- Run the downloaded Avast installer and finish setup.
- Sign in with the same Avast account and enable Sync & Backup.
- Confirm that your saved passwords, notes, and other supported vault items return before relying on autofill.
The exact package and setup screens can change over time. If the installer offers a repair or modify option, prefer that over removal when your vault status is uncertain. Never use a repackaged installer, a download from an advertising mirror, or a tool that promises to “unlock” the vault.
Could an account or Windows-password change be causing the error?
Yes, an account conflict is one of the listed possibilities, but the code alone does not prove that this is the cause. Check credentials before repeating repairs.
Also popular on Amazon
- Note: Not suitable for MacBooks released after 2023 or devices with a protruding front camera; Not applicable to full-screen or notch-style tempered glass screen protectors; Do not use on the rear camera of the phone.
- 💻 Why Do You Need a Webcam Cover Slide? — Safeguard your privacy by covering your webcam with our reliable webcam cover when not in use. Don't let anyone secretly watch you. Stay protected!
- ✅ Thin & Stylish — Enhance your laptop's functionality and aesthetics with our 0.027" ultra-thin webcam covers. Seamlessly close your laptop while adding a touch of sophistication.
- ✅ Fits Most Devices — Compatible with laptops, phones, tablets, desktops! Keep your privacy intact on Ap/ple, Mac/Book, iPh/one, iP/ad, H/P, L/novo, De/ll, Ac/er, As/us, Sa/msung devices.
- ✅ 365 Days Protection — Our upgraded 3.0 adhesive ensures a strong hold that won't damage your equipment. Experience reliable, long-term privacy protection day in and day out.
- Confirm the email address used for Avast Passwords. An account can appear to fail when the sign-in is being attempted with a different address.
- Re-enter the Avast account password carefully. If it is not accepted, use Avast’s password-reset process described in Avast’s account-login troubleshooting.
- Consider what changed immediately before the error: a Windows-account password change, a switch of Google account, or a change in organizational security policy can provide a useful diagnostic clue.
- After resetting credentials, return to Privacy > Password > Settings > Sync & Backup, sign in again, and check the synced-device list.
Google-account restrictions and Windows-account conflicts are reported as possible conditions, not universal explanations. If credentials are accepted but the service still will not synchronize, the remaining likely branches are network filtering, a damaged Avast installation, or an Avast-side service problem. Avoid sending your Avast password to anyone offering remote help; use Avast’s official support channel.
Which repair option should I try next?
Use the least destructive option that tests the most plausible cause. The table orders the choices by practical risk and reversibility rather than by a guaranteed success rate.
Free tools Windows power users keep installed
One-click scans. No signup required.
| Option | Best fit | Vault-data risk | Reversibility | What it establishes |
|---|---|---|---|---|
| Restart Windows | One-time process or session failure | Lowest | Immediate | Whether a transient process state was responsible |
| DNS and firewall checks | Avast cannot reach its services or sync stalls | Low | High; restore the original rule or setting | Whether network controls are blocking the connection |
| Turn on Sync & Backup | Desynchronization or missing device registration | Low when the account is accessible | High | Whether the vault can authenticate and register this device |
| Repair App | Damaged files or configuration | Lower than uninstalling | High | Whether Avast can repair itself in place |
| Official reinstall | Repair fails or installation is damaged | Higher if the vault is not synchronized | Lower | Whether a clean package resolves the functional failure |
| Avast Support | Persistent code after the above checks | None from contacting support | Not applicable | Whether Avast can inspect an account, service, or version-specific fault |
No published prevalence or success-rate figure is available for this code, so a “most common fix” claim would be misleading. The safest order is the one that preserves recovery options while narrowing the fault. There is also no physical hardware repair, cable, credential device, book, or other accessory that addresses this software error; buying one would not test the documented causes.
When should I contact Avast Support, and what should I include?
Contact Avast Support when the code remains after a restart, network review, synchronization attempt, and Repair App, or when you cannot verify that the vault is recoverable before an uninstall. Persistent account-service failures should also be escalated through Avast’s account support process.
Include a concise diagnostic record:
- The exact code: 0x8009000BU.
- Whether the computer runs Windows 10 or Windows 11, and its current build if known.
- The Avast product and version installed.
- Whether the Windows password changed shortly before the failure.
- Whether Sync & Backup is enabled and whether the device appears under My synced devices.
- Whether DNS or firewall settings were changed or found to block Avast.
- Every repair attempted, including the result of REPAIR APP and any reinstall attempt.
Do not send your master password, vault contents, recovery codes, or screenshots that expose saved credentials. Support needs the error and environment details, not the secrets stored in the vault. If you contact support before uninstalling, explicitly state that you are trying to preserve an unsynchronized local vault so the agent understands the urgency.
What should I avoid while troubleshooting?
- Do not permanently disable the firewall or other security controls. Use a narrow, temporary test and restore protection afterward.
- Do not delete Avast data folders or reset the app before checking sync. Unsynchronized entries may not be recoverable.
- Do not install a repackaged or unofficial installer. Use Avast’s official installation-files page.
- Do not treat the code as proof of a single cause. DNS, firewall, account, Windows-account, Google-account, and application faults require different remedies.
- Do not repeat password resets indefinitely. If the account accepts the new credentials but sync still fails, move to network, repair, or support diagnostics.
- Do not assume that a browser-extension reinstall alone repairs the product. On Windows, Avast says the Passwords extensions are paired with Avast Antivirus, so check the main application and its account connection.
How can I tell whether the vault is safe before I reinstall?
The strongest available check is a successful account sign-in with synchronization enabled and this computer visible under My synced devices. That indicates Avast has registered the device for the synchronized vault. If you cannot reach the sync controls, cannot authenticate, or see no device entry, the status of a local-only vault is uncertain; preserve the installation and ask Avast Support for guidance before removing it.
The Tool Desk
Outbyte PC Repair FREEClear out junk files and repair common Windows errorsFree Scan →Outbyte Driver Updater FREEFix the driver behind crashes, sound loss and screen glitchesFind Drivers →Also popular on Amazon
- Anti-Slip Surface - Transform your laptop into a mobile workstation with the AboveTEK portable laptop lap desk. The anti-slip surface provides a strong grip for laptops up to 15.6 inches(Diagonal), while the double rubber strip on the bottom ensures a stable display or typing experience on your lap, couch, or bed.
- Retractable Mouse Pad - Retractable laptop mouse pad extends on both directions for the left/right handed with elevation along the edges for stopping mouse from falling off. The size of laptop tray is 14" X 9.7" and the size of mouse pad is 7.4" X 6.1".
- Effective Heat Shield - The effective heat shield made of sturdy and thick material protects your laptop from overheating. Prioritizes your comfort and safety, an ideal lap pad or board for working anywhere.
- EASY to Carry and Store - With an ergonomic and simplistic design, the lap desk is portable to store in a backpack. Only 15" in size, 2.2 lb of weight and with slim 0.6 inch thickness, it is ready to be easily carried around.
- Widely Applicable - The smooth platform accommodates laptops and tablets up to 15.6 inches(Diagonal), making it a versatile accessory and one of the best gifts for mom, dad, students and professionals. Perfect for use as a laptop bed tray or tablet holder anywhere at home, library, or park.
Avast’s policy describes the stored passwords, credit cards, and notes as encrypted, but encryption does not guarantee recovery after an unsynchronized local copy is deleted. Recovery depends on having a synchronized account copy or another supported recovery path. Before a reinstall, make a written note of the account email and the exact device status, but never copy vault secrets into an unsecured document.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.What is the practical fix for 0x8009000BU?
Use this order: restart Windows; verify DNS and firewall access without weakening security permanently; enable Passwords sync and confirm the device under My synced devices; run Action Menu > Settings > General > Troubleshooting > REPAIR APP; and only then consider an official reinstall. If the code persists or the vault cannot be confirmed as recoverable, give Avast Support the exact code, Windows and Avast versions, account and sync status, recent password changes, and the steps already attempted.
Frequently Asked Questions
Will uninstalling Avast Passwords delete passwords that are not synchronized?
It can put an unsynchronized local vault at risk because there may be no server copy to restore. Confirm a successful sync and a listing under “My synced devices” before removal; if you cannot, preserve the installation and contact Avast Support.
Is error 0x8009000BU evidence that my computer has been hacked?
No. The documented possibilities are application, account, synchronization, DNS, and firewall problems, and the code does not identify malware or a security breach. Treat it as a software-access symptom while keeping Windows and your security controls enabled.
Quick wins for a faster PC:
Repair Windows errors before they cause bigger problemsFix Now →Fix the driver behind crashes, sound loss and screen glitchesFind Drivers →Can the Avast Passwords browser extension work independently of Avast Antivirus?
Avast’s product policy says the Windows Passwords browser extensions are paired with Avast Antivirus. If the antivirus installation or its account connection is damaged, the extension may be affected until the main application is repaired and synchronized.
Does Avast publish an official decoder for this exact error code?
The official Avast pages reviewed provide product, installation, and account guidance but do not decode 0x8009000BU. Troubleshooting should therefore test the documented account, network, synchronization, and application paths rather than rely on a single presumed cause.
Also popular on Amazon
- Spacious Design: Measuring 21.1" wide and 12" deep, our lap desk comfortably fits most laptops up to 15.6". Extra room for accessories ensures convenience.
- Enhanced Functionality: Packed with handy features, including a 5x9" precision tracking mouse pad and a built-in phone slot for seamless work or video calls. Plus, enjoy laptop support with the integrated device ledge.
- Cool Comfort: Enjoy a stable surface with our lap desk's dual bolster cushion, designed for comfort and airflow, keeping your lap cool during extended use.
- Durable Surface: Work with confidence on our lap desk's solid surface, featuring a blush pink color, ensuring optimal air circulation to prevent your laptop from overheating.
- On-the-Go Convenience: With an integrated handle and lightweight design (2.14 lbs), our lap desk is portable for travel or moving around the house, offering flexibility in any space.
How do I resync Avast Passwords without reinstalling it?
In Avast Antivirus, open Privacy, choose Password, open Settings, select Sync & Backup, click Turn On, sign in if prompted, and confirm the computer appears under My synced devices. Wait for synchronization to finish before making destructive changes.
Can I repair Avast without losing my saved passwords?
Use REPAIR APP from Action Menu > Settings > General > Troubleshooting before uninstalling. Repair is an in-place operation, but still confirm synchronization first because any local-only vault should be treated as at risk.
Should I disable my firewall to test the error?
Do not leave the firewall disabled. If testing is necessary, change only the relevant Avast rule temporarily, record the original setting, and restore it immediately after the test. A managed network may require its administrator to review the rule.
Do I need to buy hardware or a third-party utility for this error?
No. The documented fixes concern Windows, Avast, account access, synchronization, DNS, and firewall settings. No physical accessory or generic cleanup utility is an evidence-based solution for this code.
The Bottom Line
Protect the vault first: restart Windows, check DNS and firewall access, enable Sync & Backup, and confirm the device under My synced devices. Run Avast’s Repair App before considering removal. If reinstalling is necessary, use Avast’s official installation-files page and contact Avast Support whenever synchronization or account recovery is uncertain.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
Do these 3 things before closing this tab:
1Repair Windows errors before they cause bigger problems2Scan for outdated or missing drivers - takes under a minute3Clear out junk files and repair common Windows errors
