Save function not working in Chrome after Windows Preview Update and Chrome Update

Subject: Windows 11 / Google Chrome File System Access API — Save Works Once, Then Fails Silently

Date: November 6, 2026

I am reporting a reproducible file-saving problem involving Google Chrome on Windows 11 that appeared following substantial Chrome and Windows Preview updates.

Most importantly, I have independently reproduced the same failure using Google's own Chrome Labs File System Access API demonstration:

https://googlechromelabs.github.io/text-editor/

This establishes that our custom application is not required to reproduce the problem.

1. Description of the problem

Chrome's File System Access API behaves inconsistently when saving files to the Windows file system.

Observed behaviour:

1. Chrome can initially create and save a new file in the main OneDrive Documents directory.

Subsequent saves frequently fail silently.

Saving into subdirectories fails, including a newly created test folder outside OneDrive.

Overwriting an existing file fails.

Subsequent Save As dialogs repeatedly return to the main OneDrive Documents directory, even after another destination has been selected.

The Save As dialog closes normally, but the file is not created or updated.

No application success confirmation appears when the operation fails.

Occasionally a save succeeds again, but the failure recurs on subsequent attempts.

The behaviour resembles a file-handle, file-writing, or directory-permission state problem.

2. Independent reproduction

The same one-and-done saving failure occurs in the Chrome Labs Text Editor, which demonstrates the File System Access API.

https://googlechromelabs.github.io/text-editor/

A successful initial save is followed by failures during subsequent saves, overwrites, or attempts to select another destination.

This reproduces the failure without using any of our application code.

3. Browser and platform comparison

Google Chrome on Windows 11: Fails as described.

Microsoft Edge on the same Windows 11 computer: Saves and overwrites files successfully.

Google Chrome on macOS: Saves successfully both before and after its recent Chrome update.

Chrome Incognito on Windows: Same failure.

Local and AWS-hosted versions of our web application: Same failure in Windows Chrome.

4. Troubleshooting already performed

Updated Chrome and Windows.

Cleared Chrome's cached files.

Restarted Windows.

Tested Incognito mode.

Checked Chrome File Editing permissions.

Checked Windows Security and Malwarebytes for blocked operations.

Tested a newly created project with minimal data.

Tested saving to different directories.

Tested using Chrome Developer Tools.

None resolved the problem.

5. Recent system changes

The problem appeared after significant Google Chrome and Windows 11 Preview updates installed around November 5, 2026.

The timing suggests a possible browser/operating-system compatibility regression, but the responsible component has not been identified.

6. Technical investigation requested

Please investigate potential problems involving:

window.showSaveFilePicker()

FileSystemFileHandle.createWritable()

FileSystemWritableFileStream.write() and .close()

Windows file replacement and overwrite operations

File handle and directory access permissions

Interaction between Chrome's security sandbox and the Windows file system

File-dialog state or permission persistence after an initial successful save

Expected behaviour: Chrome should save new files, overwrite existing files, and write to user-selected directories consistently, as Microsoft Edge currently does on the same Windows computer.

Actual behaviour: Chrome intermittently saves once, then fails subsequent save operations without an actionable error.

Please advise whether this is a known regression and what diagnostic logs would help identify the failure.

Thank you.Subject: Windows 11 / Google Chrome File System Access API — Save Works Once, Then Fails Silently

Date: November 6, 2026

I am reporting a reproducible file-saving problem involving Google Chrome on Windows 11 that appeared following substantial Chrome and Windows Preview updates.

Most importantly, I have independently reproduced the same failure using Google's own Chrome Labs File System Access API demonstration:

https://googlechromelabs.github.io/text-editor/

This establishes that our custom application is not required to reproduce the problem.

1. Description of the problem

Chrome's File System Access API behaves inconsistently when saving files to the Windows file system.

Observed behaviour:

Chrome can initially create and save a new file in the main OneDrive Documents directory.

Subsequent saves frequently fail silently.

Saving into subdirectories fails, including a newly created test folder outside OneDrive.

Overwriting an existing file fails.

Subsequent Save As dialogs repeatedly return to the main OneDrive Documents directory, even after another destination has been selected.

The Save As dialog closes normally, but the file is not created or updated.

No application success confirmation appears when the operation fails.

Occasionally a save succeeds again, but the failure recurs on subsequent attempts.

The behaviour resembles a file-handle, file-writing, or directory-permission state problem.

2. Independent reproduction

The same one-and-done saving failure occurs in the Chrome Labs Text Editor, which demonstrates the File System Access API.

https://googlechromelabs.github.io/text-editor/

A successful initial save is followed by failures during subsequent saves, overwrites, or attempts to select another destination.

This reproduces the failure without using any of our application code.

3. Browser and platform comparison

Google Chrome on Windows 11: Fails as described.

Microsoft Edge on the same Windows 11 computer: Saves and overwrites files successfully.

Google Chrome on macOS: Saves successfully both before and after its recent Chrome update.

Chrome Incognito on Windows: Same failure.

Local and AWS-hosted versions of our web application: Same failure in Windows Chrome.

4. Troubleshooting already performed

Updated Chrome and Windows.

Cleared Chrome's cached files.

Restarted Windows.

Tested Incognito mode.

Checked Chrome File Editing permissions.

Checked Windows Security and Malwarebytes for blocked operations.

Tested a newly created project with minimal data.

Tested saving to different directories.

Tested using Chrome Developer Tools.

None resolved the problem.

5. Recent system changes

The problem appeared after significant Google Chrome and Windows 11 Preview updates installed around November 5, 2026.

The timing suggests a possible browser/operating-system compatibility regression, but the responsible component has not been identified.

6. Technical investigation requested

Please investigate potential problems involving:

window.showSaveFilePicker()

FileSystemFileHandle.createWritable()

FileSystemWritableFileStream.write() and .close()

Windows file replacement and overwrite operations

File handle and directory access permissions

Interaction between Chrome's security sandbox and the Windows file system

File-dialog state or permission persistence after an initial successful save

Expected behaviour: Chrome should save new files, overwrite existing files, and write to user-selected directories consistently, as Microsoft Edge currently does on the same Windows computer.

Actual behaviour: Chrome intermittently saves once, then fails subsequent save operations without an actionable error.

Please advise whether this is a known regression and what diagnostic logs would help identify the failure.

Thank you.