Fix Safari Downloading Prelanding File During Microsoft Sign-In
Question details
Users experience an unexpected prompt or automatic download of an empty file named "prelanding" from login.microsoftonline.com when attempting to sign in to Microsoft 365 using Safari.
- Product
- Microsoft 365
- Device & OS
- macOS
- Scenario
- Signing in to a Microsoft account or Microsoft 365 web service.
- Observed behavior
- Safari prompts to download or automatically downloads a zero-byte file called "prelanding" instead of smoothly completing the sign-in process.
Do not open or execute the unknown "prelanding" file on your Mac, and simply click the 'X' to cancel the download prompt when it appears.
Use an Alternative Browser and Open a Microsoft Support Ticket
Verify if the issue is isolated to Safari and involve your IT administrator to escalate the bug to Microsoft.
This behavior is widely recognized as a server-side rendering glitch occurring specifically between Safari for macOS and Microsoft's login portal. Since it requires network tracing to resolve on the backend, engaging your Microsoft 365 admin is the most effective permanent solution.
Open a different web browser on your Mac, such as Google Chrome or Mozilla Firefox, and navigate to the Microsoft 365 sign-in page to confirm if the issue is limited to Safari.
If you are using Safari and the prompt appears asking 'Do you want to download prelanding?', click the 'X' or 'Cancel' button to reject the file.
If the file downloaded automatically, navigate to your Mac's Downloads folder, right-click the 'prelanding' file, and select 'Move to Trash' without opening it.
Reach out to your organization's IT admin. Request them to open a support ticket via the Microsoft 365 admin center, as Microsoft may require network trace logs to fix this Safari-specific server bug.
Avoid Browser Login Glitches with WPS Office
If Microsoft 365 web login issues on Mac are interrupting your workflow, consider switching to WPS Office. It provides a robust, native desktop application for macOS that doesn't rely on browser-based sign-ins, offering seamless document editing and high compatibility with Microsoft formats.
- 1. Download WPS Office for Mac: Visit the official WPS Office website and download the macOS installation package.
- 2. Install and Launch: Follow the on-screen instructions to install the application and open the WPS Office workspace.
- 3. Open Your Files: Drag and drop your existing .docx, .xlsx, or .pptx files directly into WPS Office to continue working seamlessly without browser login interruptions.
Frequently Asked Questions
What is the prelanding file downloaded from Microsoft?
It is an empty, zero-byte file that erroneously triggers a download due to a server-side glitch between Safari and Microsoft's login page (login.microsoftonline.com). It is not a standard file you need for authentication.
Is the prelanding file a virus or malware?
While it originates from Microsoft's official login server and is likely just a harmless web page rendering error in Safari, you should always practice safe browsing habits by deleting unexpected files without opening them.
How can I stop Safari from downloading this file automatically?
You can go to Safari Preferences, select the Websites tab, and adjust the Downloads permissions for Microsoft websites from 'Allow' to 'Ask'. This forces Safari to prompt you, allowing you to cancel the 'prelanding' file download.
