TypeError: Cannot read properties of undefined (reading 'entities')

[ManoDaSilva]

Setup

Raspberry Pi CM4. Fresh Raspi OS Lite, 64 bit.
Radio connected with usb-serial adapter.

Replicating the issue

Installed docker and docker-compose, cloned repo with submodules. Fixed pynmea2 dep in requirements.txt.
Changed the port to match the /dev/tty[number] used (ttysUSB0 in this case).

Start each container independently, on two different terminal instances:
sudo docker start multitrack_core
sudo docker attach multitrack_core

sudo docker start nxdn_source
sudo docker attach nxdn_source

Issue

While nxdn_source the commands are arriving from the radio, an HTLM-formatted error arrives right after:

RX *NTF,CTRL,SQL,OPEN,3,-99
RX *NTF,CTRL,DBUSY,ON,3,-99
RX *NTF,IDAS,RXENCRYPT,OFF
RX *NTF,IDAS,RXRAN,1
RX NTF,IDAS,RXVCALL,TG,1,21013,3,-99
RX NTF,IDAS,RXMSG,IND,65501,21013,3,-99,GPS,"$GNRMC,[COORDINATES REDACTED],,,A77
"
[RADIO] Got a position frame from: 21013
$GNRMC,[COORDINATES REDACTED],,,A77

NMEA : [COORDINATES REDACTED - matches the expected position]

<title>Error</title>

TypeError: Cannot read properties of undefined (reading 'entities')
    at /home/node/app/server.js:188:29
    at Layer.handle [as handle_request] (/home/node/app/node_modules/express/lib/router/layer.js:95:5)
    at next (/home/node/app/node_modules/express/lib/router/route.js:149:13)
    at Route.dispatch (/home/node/app/node_modules/express/lib/router/route.js:119:3)
    at Layer.handle [as handle_request] (/home/node/app/node_modules/express/lib/router/layer.js:95:5)
    at /home/node/app/node_modules/express/lib/router/index.js:284:15
    at router.process_params (/home/node/app/node_modules/express/lib/router/index.js:346:12)
    at next (/home/node/app/node_modules/express/lib/router/index.js:280:10)
    at /home/node/app/node_modules/body-parser/lib/read.js:137:5
    at AsyncResource.runInAsyncScope (node:async_hooks:214:14)

RX *NTF,CTRL,SQL,CLOSE
RX *NTF,CTRL,DBUSY,OFF
TIMEOUT_ERROR

On multitrack_core, the following appears:

Received data from plugin
No main_ID found in db.json
TypeError: Cannot read properties of undefined (reading 'entities')
at /home/node/app/server.js:188:29
at Layer.handle [as handle_request] (/home/node/app/node_modules/express/lib/router/layer.js:95:5)
at next (/home/node/app/node_modules/express/lib/router/route.js:149:13)
at Route.dispatch (/home/node/app/node_modules/express/lib/router/route.js:119:3)
at Layer.handle [as handle_request] (/home/node/app/node_modules/express/lib/router/layer.js:95:5)
at /home/node/app/node_modules/express/lib/router/index.js:284:15
at router.process_params (/home/node/app/node_modules/express/lib/router/index.js:346:12)
at next (/home/node/app/node_modules/express/lib/router/index.js:280:10)
at /home/node/app/node_modules/body-parser/lib/read.js:137:5
at AsyncResource.runInAsyncScope (node:async_hooks:214:14)

[ManoDaSilva]

Adding that data coming from dummy_source seems to work when started as well, as per this output from multitrack_core:

Received subscription request Got source : dummy_source
Received data from plugin
Received data from plugin
Received data from plugin
Received data from plugin
Received data from plugin
Received data from plugin
Received data from plugin
Received data from plugin
Received data from plugin
Received data from plugin
Received data from plugin
Received data from plugin
Received data from plugin
{
type: 'identify_plugin',
main_ID: 'dummy_source',
actions: [ 'stun', 'kill', 'revive' ],
text: true,
position: true,
status: true,
listen_port: '8500'
}
db : {
'main-id': {
type: 'identify_plugin',
main_ID: 'main-id',
actions: [ 'different', 'actions', 'here' ],
text: true,
position: true,
status: true,
listen_port: 0,
entities: { sn0000: [Object] }
},
dummy_source: {
type: 'identify_plugin',
main_ID: 'dummy_source',
actions: [ 'stun', 'kill', 'revive' ],
text: true,
position: true,
status: true,
listen_port: '8500',
entities: { '0001': [Object] }
}
}
Received subscription request Got source : dummy_source

However, no additional point shows up in the GUI.