Seahub 7 - bad magic number


I use Seafile server and Seahub on FreeBSD 12 with an sqlite backend :

libsearpc-3.2.0_1,1            Simple RPC framework based on GObject System in C
py37-seafdav-7.1.8             Python library for accessing seafile data model
py37-seafobj-7.1.8             Python library for accessing seafile data model
seafile-server-7.1.5           Open Source Cloud Storage (Server)
seahub-7.1.8                   Web frontend for Seafile

When i try to start Seahub, i have this error :

 /usr/local/etc/rc.d/seahub onerestart
Seahub is not running
LANG is not set in ENV, set to en_US.UTF-8
LC_ALL is not set in ENV, set to en_US.UTF-8
Starting seahub at port 8000 ...
Traceback (most recent call last):
  File "/usr/local/bin/gunicorn-3.7", line 11, in <module>
    load_entry_point('gunicorn==19.9.0', 'console_scripts', 'gunicorn')()
  File "/usr/local/lib/python3.7/site-packages/gunicorn/app/", line 61, in run
    WSGIApplication("%(prog)s [OPTIONS] [APP_MODULE]").run()
  File "/usr/local/lib/python3.7/site-packages/gunicorn/app/", line 223, in run
    super(Application, self).run()
  File "/usr/local/lib/python3.7/site-packages/gunicorn/app/", line 72, in run
  File "/usr/local/lib/python3.7/site-packages/gunicorn/", line 60, in __init__
  File "/usr/local/lib/python3.7/site-packages/gunicorn/", line 120, in setup
  File "/usr/local/lib/python3.7/site-packages/gunicorn/app/", line 67, in wsgi
    self.callable = self.load()
  File "/usr/local/lib/python3.7/site-packages/gunicorn/app/", line 52, in load
    return self.load_wsgiapp()
  File "/usr/local/lib/python3.7/site-packages/gunicorn/app/", line 41, in load_wsgiapp
    return util.import_app(self.app_uri)
  File "/usr/local/lib/python3.7/site-packages/gunicorn/", line 350, in import_app
  File "/usr/local/www/haiwen/seafile-server/seahub/seahub/", line 25, in <module>
    application = get_wsgi_application()
  File "/usr/local/lib/python3.7/site-packages/django/core/", line 13, in get_wsgi_application
  File "/usr/local/lib/python3.7/site-packages/django/", line 27, in setup
  File "/usr/local/lib/python3.7/site-packages/django/apps/", line 108, in populate
  File "/usr/local/lib/python3.7/site-packages/django/apps/", line 202, in import_models
    self.models_module = import_module(models_module_name)
  File "/usr/local/lib/python3.7/importlib/", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
ImportError: bad magic number in '': b'\x03\xf3\r\n'
Error:Seahub failed to start.
Please try to run "./ start" again

Where can i look to try to fix this issue?