Unfortunately I’m personally not using PostgreSQL but MariaDB, so that I cannot tell you the exact command syntax. You can try to create the missing table on your own, if you don’t want to reinstall the talk app as recommend in the other discussions. Please make always sure that you’ve created a backup of your database before you modify anything.
Here you find the table structure:
> describe oc_talk_participants;
+----------------------+----------------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+----------------------+----------------------+------+-----+---------+-------+
| user_id | varchar(255) | YES | MUL | NULL | |
| room_id | int(10) unsigned | NO | MUL | 0 | |
| last_ping | int(10) unsigned | NO | MUL | 0 | |
| session_id | varchar(255) | NO | MUL | | |
| participant_type | smallint(5) unsigned | NO | | 0 | |
| favorite | tinyint(1) | NO | | 0 | |
| in_call | int(11) | NO | MUL | 0 | |
| notification_level | int(11) | YES | | 0 | |
| last_joined_call | datetime | YES | | NULL | |
| last_read_message | bigint(20) | YES | | 0 | |
| last_mention_message | bigint(20) | YES | | 0 | |
+----------------------+----------------------+------+-----+---------+-------+
11 rows in set (0.00 sec)