Troubleshooting Tip: Error during captive portal user registration under high load

Description

This article describes how to troubleshoot a high load of users registering for captive portal user self-registration.

Scope

FortiAuthenticator v6.6.8 build 1890.

Solution

To confirm this issue need to run RADIUS debug on FortiAuthenticator. To do so, head to https://fac-ip/debug/radius and enable the detailed debug mode by pressing the debug mode button twice until it says 'Detailed debugging active'.

The log displays:

KeyError: 'email_verify'
2026-02-25 18:02:42,408 error django.request log 4527 139934961694400 Internal Server Error: /portal/register/
Traceback (most recent call last):
  File "/lib/python3.11/site-packages/django/core/handlers/exception.py", line 55, in inner
    response = get_response(request)
               ^^^^^^^^^^^^^^^^^^^^^
  File "/lib/python3.11/site-packages/django/core/handlers/base.py", line 197, in getresponse
    response = wrapped_callback(request, callback_args, *callback_kwargs)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/lib/python3.11/site-packages/django/views/generic/base.py", line 105, in view
    return self.dispatch(request, args, *kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/lib/python3.11/site-packages/django/utils/decorators.py", line 46, in wrapper
    return boundmethod(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/lib/python3.11/site-packages/csp/decorators.py", line 7, in wrapped
    r = f(*a, **kw)
        ^^^^^^^^^^^
  File "./fac/fac/apps/guest/views/registration.py", line 314, in dispatch
  File "/lib/python3.11/site-packages/formtools/wizard/views.py", line 250, in dispatch
    response = super().dispatch(request, args, *kwargs)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/lib/python3.11/site-packages/django/views/generic/base.py", line 144, in dispatch
    return handler(request, args, *kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "./fac/fac/apps/facauth/views/registration.py", line 539, in post
  File "/lib/python3.11/site-packages/formtools/wizard/views.py", line 297, in post
    form = self.get_form(data=self.request.POST, files=self.request.FILES)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/lib/python3.11/site-packages/formtools/wizard/views.py", line 415, in get_form
    form_class = self.get_form_list()[step]

This error has been recorded with the ID 1262280, and the fix has been released with version 6.6.10.