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btey
Staff & Editor
btey
Staff & Editor
November 11, 2025

Troubleshooting Tip: HTTP header length is too long

  • November 11, 2025
  • 0 replies
  • 408 views
Description This article describes how to troubleshoot and resolve an 'HTTP header length is too long' error.
Scope FortiAuthenticator 6.6.7 and 8.0.0.
Solution

The following error may be encountered while accessing the FortiAuthenticator portal:

 

HTTP header length is too long.jpg

 

  1. Check the HTTP request header length.
  2. To resolve, increase the 'Maximum HTTP header length' if needed (System -> Administrator -> System Access -> GUI Access -> Maximum HTTP header length). Default Maximum HTTP header length is 4KB. Values from 4 KB to 16 KB can be set.

 

Related article: 
For more information on adjusting system access settings, see System access - FortiAuthenticator 8.0.0.
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