My instance of Kali Linux Everything 2025.2 was running a previous version of kismet fine with the same hardware setup. Having just done an apt update it now doesn't want to stay running and hits this fatal error after I get logged in and try to open the Data Sources for the first time.

FATAL: Encountered an error receiving data from Kismet 'bytearray' object has no attribute 'encode'

I was always running as sudo but have also added the kali account to the kismet group and restarted but now it keeps hitting this same error whether sudo or not.

I've done some searching and can't see others with this issue and don't see any previously raised issues with the same problem. Any hints or solutions welcomed. It just seems to be since updating.

I can browse around the settings and the rest of the UI but it falls over when I go back to "Data Sources". I have removed my external Wi-Fi and so the only remaining devices are internal to my laptop.

└─$ kismet
INFO: Including sub-config file: /etc/kismet/kismet_httpd.conf
INFO: Including sub-config file: /etc/kismet/kismet_memory.conf
INFO: Including sub-config file: /etc/kismet/kismet_alerts.conf
INFO: Including sub-config file: /etc/kismet/kismet_80211.conf
INFO: Including sub-config file: /etc/kismet/kismet_logging.conf
INFO: Including sub-config file: /etc/kismet/kismet_filter.conf
INFO: Including sub-config file: /etc/kismet/kismet_uav.conf
INFO: Loading config override file '/etc/kismet/kismet_package.conf'
INFO: Optional sub-config file not present: /etc/kismet/kismet_package.conf
INFO: Loading config override file '/etc/kismet/kismet_site.conf'
INFO: Optional sub-config file not present: /etc/kismet/kismet_site.conf

INFO: GPS track will be logged to the Kismet logfile
INFO: Starting Kismet web server...
INFO: HTTP server listening on 0.0.0.0:2501
INFO: Could not open system plugin directory (/usr/lib/x86_64-linux-gnu/kis
met/), skipping: No such file or directory
INFO: Did not find a user plugin directory (/home/kali/.kismet//plugins/),
skipping: No such file or directory
FATAL: Encountered an error receiving data from Kismet 'bytearray' object has no attribute 'encode'

┌──(kali㉿kali)-[~]
└─$ sudo kismet
INFO: Including sub-config file: /etc/kismet/kismet_httpd.conf
INFO: Including sub-config file: /etc/kismet/kismet_memory.conf
INFO: Including sub-config file: /etc/kismet/kismet_alerts.conf
INFO: Including sub-config file: /etc/kismet/kismet_80211.conf
INFO: Including sub-config file: /etc/kismet/kismet_logging.conf
INFO: Including sub-config file: /etc/kismet/kismet_filter.conf
INFO: Including sub-config file: /etc/kismet/kismet_uav.conf
INFO: Loading config override file '/etc/kismet/kismet_package.conf'
INFO: Optional sub-config file not present: /etc/kismet/kismet_package.conf
INFO: Loading config override file '/etc/kismet/kismet_site.conf'
INFO: Optional sub-config file not present: /etc/kismet/kismet_site.conf
KISMET - Point your browser to http://localhost:2501 (or the address of this sessions.
INFO: Serving static file content from /usr/share/kismet/httpd/
INFO: Enabling channel hopping by default on sources which support channel
control.
INFO: Setting default channel hop rate to 5/sec
INFO: Enabling channel list splitting on sources which share the same list
of channels
INFO: Enabling channel list shuffling to optimize overlaps
INFO: Sources will be re-opened if they encounter an error
INFO: Saving datasources to the Kismet database log every 30 seconds
INFO: Launching remote capture server on 127.0.0.1 3501
INFO: No data sources defined; Kismet will not capture anything until a
source is added.
INFO: Opened kismetdb log file './/Kismet-20251104-11-12-18-1.kismet'
INFO: Saving packets to the Kismet database log.
INFO: GPS track will be logged to the Kismet logfile
ALERT: ROOTUSER Kismet is running as root; this is less secure. If you
are running Kismet at boot via systemd, make sure to use systemctl edit kismet.service to change the user. For more information, see
the Kismet README for setting up Kismet with minimal privileges.
INFO: Starting Kismet web server...
INFO: HTTP server listening on 0.0.0.0:2501
INFO: Could not open system plugin directory (/usr/lib/x86_64-linux-gnu/kis
met/), skipping: No such file or directory
INFO: Did not find a user plugin directory (/root/.kismet//plugins/),
skipping: No such file or directory
FATAL: Encountered an error receiving data from Kismet 'bytearray' object has no attribute 'encode'