Error: Unable to write pid file / mqtt broker - access from remote - raspberry-pi

Question

I have been reading Eclipse mqtt documentations and relevant posts about the MQTT Broker failing to start and have implemented the suggestions and ideas which seem relevant to the solution of my problem. However as newbe I am now stuck and require more support to get Broker started and accessable from remote
I'm using Raspberry Pi OS Bullseye & Mosquitto version 2.0.11
mosquitto.conf is created in /etc/mosquitto:
pid_file /var/run/mosquitto/mosquitto.pid
per_listener_settings true
persistence true
persistence_file mosquitto.db
persistence_location /var/lib/mosquitto/
log_dest file /var/log/mosquitto.log
include_dir /etc/mosquitto/conf.d
listener 1883 192.168.1.99
protocol mqtt
log_type all
acl_file /etc/mosquitto/acls
allow-anonymous false
connection_messages true
max_keepalive 10
log_timestamp true
log_dest topic
log_dest syslog
log_dest stdout
log_type all
password_file /etc/mosquitto/pwfile
and local.conf in /etc/mosquitto/conf.d to separate local access from remote access
allow_anonymous true
listener 1883 localhost
Updated /lib/systemd/system/mosquitto.service to:
ExecStartPre=/bin/mkdir -m 740 -p /var/run/mosquitto
ExecStartPre=/bin/chown mosquitto /var/run/mosquitto
(Have tried chown mosquitto:.., chown mosquitto:mosquitto.., chown -hR mosq... and chown -R mosq...)
Rights: /var/run/mosquitto/mosquitto.pid
drwxr----- 2 mosquitto root 60 Dec 16 10:14 .
drwxr-xr-x 33 root root 1000 Dec 16 14:46 ..
-rw-r--r-- 1 mosquitto mosquitto 4 Dec 16 10:14 mosquitto.pid
Broker is started with:
mosquitto -c /etc/mosquitto/mosquitto.conf -v
Error message returned:
1639655912: Loading config file /etc/mosquitto/conf.d/local.conf
2021-12-16|12:58:32: Error: Unable to write pid file
when I sudo delete mosquitto.pid or sudo rename its directory and restart mosquitto daemon, a new mosquitto.pid is not created and I get same error message as above
Command "systemctl status mosquitto.service" returns:
Warning: The unit file, source configuration file or drop-ins of mosquitto.service
changed on disk. Run 'systemctl daemon-reload' to reload >
mosquitto.service - Mosquitto MQTT Broker
Loaded: loaded (/lib/systemd/system/mosquitto.service; enabled; vendor preset: enabled)
Active: failed (Result: exit-code) since Thu 2021-12-16 10:14:03 CET; 2h 56min ago
Process: 5035 ExecStartPre=/bin/mkdir -m 740 -p /var/log/mosquitto (code=exited, status=0/SUCCESS)
Process: 5036 ExecStartPre=/bin/chown mosquitto /var/log/mosquitto (code=exited, status=0/SUCCESS)
Process: 5037 ExecStartPre=/bin/mkdir -m 740 -p /var/run/mosquitto (code=exited, status=0/SUCCESS)
Process: 5038 ExecStartPre=/bin/chown mosquitto /var/run/mosquitto (code=exited, status=0/SUCCESS)
Process: 5039 ExecStart=/usr/sbin/mosquitto -c /etc/mosquitto/mosquitto.conf (code=exited, status=3)
Main PID: 5039 (code=exited, status=3)
Dec 16 10:14:03 Pi4 systemd[1]: mosquitto.service: Scheduled restart job, restart counter is at 5.
Dec 16 10:14:03 Pi4 systemd[1]: Stopped Mosquitto MQTT Broker.
Dec 16 10:14:03 Pi4 systemd[1]: mosquitto.service: Start request repeated too quickly.
Dec 16 10:14:03 Pi4 systemd[1]: mosquitto.service: Failed with result 'exit-code'.
Dec 16 10:14:03 Pi4 systemd[1]: Failed to start Mosquitto MQTT Broker.
I appreciate any guidance or help

Answer 1

Generate a new client ID. I'm testing mine using MQTTLENS which is a Chrome app. Once I did this the problem stopped and everything is working ok.