502 internal server error while trying to load one users info on system admin panel

Hi,

When I’m trying to see the info for a user from system admin panel, it starts loading the page for a long time and then it just shows 502 Internal server error.

All else works fine, I cann see info for every other user. The user in question can sync and access seahub whith his credentials.

I ve run the fsck repair, upgraded to the latest version 6.3.4 of the seafile server, but the problem persists.

Proxy Error
The proxy server received an invalid response from an upstream server.
The proxy server could not handle the request GET /useradmin/info/user@domain.tld/.

Reason: Error reading from remote server

seahub.log

2019-02-03 07:08:39,176 [ERROR] django.request:135 handle_uncaught_exception Internal Server Error: /api2/ping/
Traceback (most recent call last):
File “/seafile-server-6.3.4/seahub/thirdpart/django/core/handlers/exception.py”, line 41, in inner
response = get_response(request)
File “seafile-server-6.3.4/seahub/thirdpart/django/core/handlers/base.py”, line 244, in _legacy_get_response
response = middleware_method(request)
File " seafile-server-6.3.4/seahub/thirdpart/termsandconditions/middleware.py", line 23, in process_request
if not config.ENABLE_TERMS_AND_CONDITIONS:
File " seafile-server-6.3.4/seahub/thirdpart/django/utils/functional.py", line 238, in inner
self._setup()
File " seafile-server-6.3.4/seahub/thirdpart/constance/init.py", line 11, in _setup
self._wrapped = Config()
File " seafile-server-6.3.4/seahub/thirdpart/constance/base.py", line 10, in init
utils.import_module_attr(settings.BACKEND)())
File " seafile-server-6.3.4/seahub/thirdpart/constance/backends/database/init.py", line 34, in init
self.autofill()
File " seafile-server-6.3.4/seahub/thirdpart/constance/backends/database/init.py", line 45, in autofill
if self._cache.get(full_cachekey):
File " seafile-server-6.3.4/seahub/thirdpart/django/core/cache/backends/memcached.py", line 79, in get
val = self._cache.get(key)
Error: error 26 from memcached_get(:1:autofilled): Transport endpoint is not connected

Thank you very much

Best regards