Error when execute insert/update

Hi guys, I have a PostgreSQL 9.5 server, which started showing the
following message in the log:

,ERROR,54000,"multixact ""members"" limit exceeded","This command
would create a multixact with 2 members, but the remaining space is
only enough for 0 members.","Run a database-wide VACUUM in database
with OID 139059 with reduced vacuum_multixact_freeze_min_age and
vacuum_multixact_freeze_table_age settings.",,,"SQL statement ""SELECT
1 FROM ONLY ""public"".""alf_server"" x WHERE ""id""
OPERATOR(pg_catalog.=) $1 FOR KEY SHARE OF x""","insert into

I started the vacuum in the database , but the same for the size ,I
believe it will take a long time. Is there any way to increase this
limit member while the vacuum is running to free up the application?

thanks a lot,