Network / firewall ?

firebird.driver.types.DatabaseError: Unable to complete network request to host "localhost".
-Failed to establish a connection.

LOG DETAILS:

2025-07-20 18:12:09.095
2025-07-20 18:12:09.095 act_db_main = <firebird.qa.plugin.Action object at [hex]>
2025-07-20 18:12:09.096 act_db_repl = <firebird.qa.plugin.Action object at [hex]>
2025-07-20 18:12:09.096 tmp_data = WindowsPath('H:/QA/temp/qa2024.tmp/fbqa/test_12093/tmp_blob_for_replication.dat')
2025-07-20 18:12:09.096 capsys = <_pytest.capture.CaptureFixture object at [hex]>
2025-07-20 18:12:09.096
2025-07-20 18:12:09.096     @pytest.mark.replication
2025-07-20 18:12:09.096     @pytest.mark.version('>=4.0.1')
2025-07-20 18:12:09.096     def test_1(act_db_main: Action,  act_db_repl: Action, tmp_data: Path, capsys):
2025-07-20 18:12:09.096
2025-07-20 18:12:09.096         out_prep, out_main, out_drop = '', '', ''
2025-07-20 18:12:09.096
2025-07-20 18:12:09.096         # Obtain full path + filename for DB_MAIN and DB_REPL aliases.
2

[...SKIPPED...]

n(dpb), dpb)
2025-07-20 18:12:09.106 >       self._check()
2025-07-20 18:12:09.106
2025-07-20 18:12:09.106 C:\Python3x\Lib\site-packages\firebird\driver\interfaces.py:1300:
2025-07-20 18:12:09.106 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
2025-07-20 18:12:09.106
2025-07-20 18:12:09.106 self = <firebird.driver.interfaces.iProvider object at [hex]>
2025-07-20 18:12:09.106
2025-07-20 18:12:09.106     def _check(self) -> None:
2025-07-20 18:12:09.106         state = self.status.get_state()
2025-07-20 18:12:09.106         if StateFlag.ERRORS in state:
2025-07-20 18:12:09.106 >           raise self.__report(DatabaseError, self.status.get_errors())
2025-07-20 18:12:09.106 E           firebird.driver.types.DatabaseError: Unable to complete network request to host "localhost".
2025-07-20 18:12:09.106 E           -Failed to establish a connection.
2025-07-20 18:12:09.106
2025-07-20 18:12:09.106 C:\Python3x\Lib\site-packages\firebird\driver\interfaces.py:113: DatabaseError