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Bryce McMillan's avatar
Bryce McMillan
Iron Contributor
Apr 12, 2022
Solved

SharePoint Online showing blank page on Firefox 99.0

Hey All,   Is anyone else experiencing dead end page loads for any SharePoint Online destination when using Firefox version 99.0?   If I browse to the standard https://<domain>.sharepoint.com/_la...
SharePoint Online
  • Bryce McMillan's avatar
    Bryce McMillan
    Apr 20, 2022
    Microsoft have updated and completed the fix to rectify this situation under service advisory SP357692. Fix and last update confirmed on Thursday, April 14, 2022, 2:00 AM (4/13/2022, 4:00 PM UTC).
Bryce McMillan's avatar
Bryce McMillan
Iron Contributor
Apr 20, 2022
Microsoft have updated and completed the fix to rectify this situation under service advisory SP357692. Fix and last update confirmed on Thursday, April 14, 2022, 2:00 AM (4/13/2022, 4:00 PM UTC).
RangoLv's avatar
RangoLv
Copper Contributor
Nov 15, 2023

Bryce McMillan It seems to be a related issue. Here is the detailed description of the problem and the testing situation. Firefox 119.0.1 (64-bit).

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Problem Description Issue: Users experience interrupted downloads when using Firefox to download large files from SharePoint, particularly under slower network speeds. This issue does not occur in Chrome under identical network and device conditions.

 

Solution Debugging and Resolution:

Initial Observation: Utilized Firefox's debugging tools to monitor and analyze the download process. Downloads were failing in Firefox with an error message indicating a ServiceWorker issue: "Failed to load ‘’. A ServiceWorker intercepted the request and encountered an unexpected error.". Key Action: Unregistered SharePoint ServiceWorkers within Firefox. Outcome: Subsequent tests showed no interruptions in the download process, confirming that ServiceWorkers were the root cause of the problem.

 

Analysis of Potential Causes

Different Handling of ServiceWorkers:Browsers' Diverse Strategies: Various browsers have distinct policies and methods for managing ServiceWorkers. Firefox's Specifics: Firefox may implement stricter security measures or different handling mechanisms that are not compatible with SharePoint's ServiceWorker configurations, leading to download interruptions.

 

Recommendations

For Users: Temporarily unregister ServiceWorkers in Firefox if encountering similar download issues with SharePoint. For Developers: Investigate and address the compatibility issues between SharePoint's ServiceWorkers and Firefox to prevent download interruptions.

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