On attempting to login to the database server I get an error message "readonly attribute" - see log entry below

I'm using postgresql 9.6 on Ubuntu 16.04.4 LTS,  installed on a single user workstation using trust authentication on 127.0.0.1
pgadmin 4.3 installed using apt from the postgresql repository

No problems with pgadmin3 or pgadmin 4.21

Any thoughts on how to proceed would be much appreciated

Thanks

Tony

2018-04-18 19:10:59,709: ERROR    pgadmin:    readonly attribute
Traceback (most recent call last):
  File "/usr/share/pgadmin4/web/pgadmin/browser/server_groups/servers/__init__.py", line 972, in connect
    server_types=ServerType.types()
  File "/usr/share/pgadmin4/web/pgadmin/utils/driver/psycopg2/connection.py", line 313, in connect
    pg_conn.notices = deque([], self.ASYNC_NOTICE_MAXLENGTH)
AttributeError: readonly attribute