AT THE TIME OF RESTARTING THE SERVER ODOO GIVES ME AN ERROR ALMOST WHEN ENDING

THIS IS THE  ERROR....

2020-10-10 13:43:04,718 3018 INFO ? odoo: Odoo version 12.0 

2020-10-10 13:43:04,719 3018 INFO ? odoo: addons paths: ['/home/administrador/.local/share/Odoo/addons/12.0', '/opt/odoo/odoo/odoo/addons', '/opt/odoo/odoo/addons'] 

2020-10-10 13:43:04,719 3018 INFO ? odoo: database: default@default:default 

2020-10-10 13:43:05,220 3018 INFO ? odoo.addons.base.models.ir_actions_report: Will use the Wkhtmltopdf binary at /usr/local/bin/wkhtmltopdf 

2020-10-10 13:43:05,490 3018 INFO ? odoo.service.server: HTTP service (werkzeug) running on administrador-VirtualBox:8069 

2020-10-10 13:45:13,562 3018 INFO ? odoo.http: HTTP Configuring static files 

2020-10-10 13:45:13,574 3018 INFO ? odoo.sql_db: Connection to the database failed 

2020-10-10 13:45:13,587 3018 INFO ? werkzeug: 127.0.0.1 - - [10/Oct/2020 13:45:13] "GET / HTTP/1.1" 500 - 0 0.000 0.022

2020-10-10 13:45:13,598 3018 ERROR ? werkzeug: Error on request:

Traceback (most recent call last):

  File "/home/administrador/.local/lib/python3.6/site-packages/werkzeug/serving.py", line 304, in run_wsgi

    execute(self.server.app)

  File "/home/administrador/.local/lib/python3.6/site-packages/werkzeug/serving.py", line 292, in execute

    application_iter = app(environ, start_response)

  File "/opt/odoo/odoo/odoo/service/server.py", line 434, in app

    return self.app(e, s)

  File "/opt/odoo/odoo/odoo/service/wsgi_server.py", line 142, in application

    return application_unproxied(environ, start_response)

  File "/opt/odoo/odoo/odoo/service/wsgi_server.py", line 117, in application_unproxied

    result = odoo.http.root(environ, start_response)

  File "/opt/odoo/odoo/odoo/http.py", line 1320, in _call_

    return self.dispatch(environ, start_response)

  File "/opt/odoo/odoo/odoo/http.py", line 1293, in _call_

    return self.app(environ, start_wrapped)

  File "/home/administrador/.local/lib/python3.6/site-packages/werkzeug/middleware/shared_data.py", line 220, in _call_

    return self.app(environ, start_response)

  File "/opt/odoo/odoo/odoo/http.py", line 1453, in dispatch

    self.setup_db(httprequest)

  File "/opt/odoo/odoo/odoo/http.py", line 1376, in setup_db

    httprequest.session.db = db_monodb(httprequest)

  File "/opt/odoo/odoo/odoo/http.py", line 1537, in db_monodb

    dbs = db_list(True, httprequest)

  File "/opt/odoo/odoo/odoo/http.py", line 1504, in db_list

    dbs = odoo.service.db.list_dbs(force)

  File "/opt/odoo/odoo/odoo/service/db.py", line 375, in list_dbs

    with closing(db.cursor()) as cr:

  File "/opt/odoo/odoo/odoo/sql_db.py", line 657, in cursor

    return Cursor(self.__pool, self.dbname, self.dsn, serialized=serialized)

  File "/opt/odoo/odoo/odoo/sql_db.py", line 171, in _init_

    self._cnx = pool.borrow(dsn)

  File "/opt/odoo/odoo/odoo/sql_db.py", line 540, in _locked

    return fun(self, *args, **kwargs)

  File "/opt/odoo/odoo/odoo/sql_db.py", line 608, in borrow

    **connection_info)

  File "/home/administrador/.local/lib/python3.6/site-packages/psycopg2/_init_.py", line 127, in connect

    conn = _connect(dsn, connection_factory=connection_factory, **kwasync)

psycopg2.OperationalError: FATAL:  role "administrador" does not exist - - -

 WHEN I WRITE ON THE WEB THE LOCALHOST GIVES ME AN ERROR

Internal Server Error

The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application