Error on Upgrade 3.12.3

I was performing a PrivacyIdea upgrade operation via PiP, but a network operation error occurred. Since then, the system only displays the message:
“Internal Server Error”

I am getting the following message in the logs:

Traceback (most recent call last):

Traceback (most recent call last):
  File "/opt/privacyidea/lib/python3.9/site-packages/flask/app.py", line 1473, in wsgi_app
  File "/opt/privacyidea/lib/python3.9/site-packages/flask/app.py", line 882, in full_dispatch_request
    be a response object.  In order to convert the return value to a
  File "/opt/privacyidea/lib/python3.9/site-packages/flask/app.py", line 878, in full_dispatch_request
  File "/opt/privacyidea/lib/python3.9/site-packages/flask/app.py", line 1253, in preprocess_request
    " Response instance, or WSGI callable, but it was a"
  File "/opt/privacyidea/lib/python3.9/site-packages/privacyidea/webui/login.py", line 73, in before_request
    g.client_ip = get_client_ip(request, get_from_config(SYSCONF.OVERRIDECLIENT))
  File "/opt/privacyidea/lib/python3.9/site-packages/privacyidea/lib/log.py", line 144, in log_wrapper
    self.hide_args = hide_args or []
  File "/opt/privacyidea/lib/python3.9/site-packages/privacyidea/lib/config.py", line 371, in get_from_config
  File "/opt/privacyidea/lib/python3.9/site-packages/privacyidea/lib/config.py", line 351, in get_config_object
    If the request-local store contains no config object, do nothing.
  File "/opt/privacyidea/lib/python3.9/site-packages/privacyidea/lib/config.py", line 203, in reload_and_clone
    self.config = config
  File "/opt/privacyidea/lib/python3.9/site-packages/privacyidea/lib/config.py", line 105, in _reload_from_db
    :return:
  File "/opt/privacyidea/lib/python3.9/site-packages/sqlalchemy/orm/query.py", line 2824, in first
    return self.limit(1)._iter().first()
  File "/opt/privacyidea/lib/python3.9/site-packages/sqlalchemy/orm/query.py", line 2916, in _iter
    result = self.session.execute(
  File "/opt/privacyidea/lib/python3.9/site-packages/sqlalchemy/orm/session.py", line 1717, in execute
    result = conn._execute_20(statement, params or {}, execution_options)
  File "/opt/privacyidea/lib/python3.9/site-packages/sqlalchemy/engine/base.py", line 1710, in _execute_20
    return meth(self, args_10style, kwargs_10style, execution_options)
  File "/opt/privacyidea/lib/python3.9/site-packages/sqlalchemy/sql/elements.py", line 334, in _execute_on_connection
    return connection._execute_clauseelement(
  File "/opt/privacyidea/lib/python3.9/site-packages/sqlalchemy/engine/base.py", line 1577, in _execute_clauseelement
    ret = self._execute_context(
  File "/opt/privacyidea/lib/python3.9/site-packages/sqlalchemy/engine/base.py", line 1953, in _execute_context
    self._handle_dbapi_exception(
  File "/opt/privacyidea/lib/python3.9/site-packages/sqlalchemy/engine/base.py", line 2134, in _handle_dbapi_exception
    util.raise_(
  File "/opt/privacyidea/lib/python3.9/site-packages/sqlalchemy/util/compat.py", line 211, in raise_
    raise exception
  File "/opt/privacyidea/lib/python3.9/site-packages/sqlalchemy/engine/base.py", line 1910, in _execute_context
    self.dialect.do_execute(
  File "/opt/privacyidea/lib/python3.9/site-packages/sqlalchemy/engine/default.py", line 736, in do_execute
    cursor.execute(statement, parameters)
sqlalchemy.exc.OperationalError: (psycopg2.OperationalError) SSL SYSCALL error: EOF detected

[SQL: SELECT config."Key" AS "config_Key", config."Value" AS "config_Value", config."Type" AS "config_Type", config."Description" AS "config_Description"
FROM config
WHERE config."Key" = %(Key_1)s
 LIMIT %(param_1)s]
[parameters: {'Key_1': '__timestamp__', 'param_1': 1}]
(Background on this error at: https://sqlalche.me/e/14/e3q8)

3.11.2 → 3.12.3

Any help is welcome.

a) Where does this error occur?
Obviously not during the update?

b) How did you run the update?
Did you follow this guide?
2.4. Upgrading — privacyIDEA 0.0+g2e55c4b4d documentation

c) What was the output during the update?

d) It is a DB error. You are using postgres?
Did you run the schema update successfully?

When you asking yourself these questions, you will probably get a clue.