WatchGuard Support Center

Knowledge Base - Article

 Reverse Proxy fails with blank page displayed for some applications

Products: Firebox Cloud
Products: Firebox & XTM
Operating System: 12.5.x
Issue Status: Open
Tracking ID: FBX-17336
Status: Open
Resolved In:
With some applications, the reverse proxy fails to display a page for users, or users see the error message: net::ERR_CONTENT_LENGTH_MISMATCH
This occurs because of a buffer overflow error with the reverse proxy. To confirm that you are experiencing a buffer overflow error:
  1. Set the Diagnostic Log Level for Security Subscriptions > Access Portal to Debug.
    For instructions, see Set the Diagnostic Log Level.
  2. In Firebox System Manager or Web UI, open Traffic Monitor.
    For instructions, see Traffic Monitor.
    If your network environment is large or extremely busy, the content of Traffic Monitor might scroll too quickly to identify this log message. In this case, you can use a log tool such as WatchGuard Cloud. To learn more, see About Firebox Logging and Notification
  3. Try to get access  to an application that fails with reverse proxy.  
  4. Review the log messages that appear on the Traffic Monitor > Diagnostic tab. If this is the issue, you see a log message that looks like this:
    2019-11-15 13:52:10 wrapper nginx: 2019/11/15 13:52:10 [crit] 6164#0: *140605 pwritev() "/var/run/nginx/nginx_proxy/0000002612" has written only 12288 of 32768 while reading upstream, client:, server: Debug
No workaround exists at this time.