Error starting subflow

I am using node-red with home assistant and during a recent upgrades it caused node-red to start crashing. looking at the logs I found this error I couldn't get rid of. Not sure where to look the stack trace points to Subflow a not being able to start, but what should I look for in there? functionally everything seems to be working.

TypeError: Cannot read properties of undefined (reading 'id')
    at /opt/node_modules/@node-red/runtime/lib/flows/Subflow.js:209:140
    at Array.map (<anonymous>)
    at /opt/node_modules/@node-red/runtime/lib/flows/Subflow.js:209:95
    at Array.map (<anonymous>)
    at Subflow.start (/opt/node_modules/@node-red/runtime/lib/flows/Subflow.js:209:62)
    at Flow.start (/opt/node_modules/@node-red/runtime/lib/flows/Flow.js:224:41)
    at start (/opt/node_modules/@node-red/runtime/lib/flows/index.js:394:33)

Exactly what version of Node-RED have you got? Check the bottom of the main menu in the Node-RED editor - the home assistant packaging uses different version numbers to those we use.

Running 3.0.2. and HA-Addon version is 13.3.1

bit more trace logging if that helps identify which flow/node is causing me grief.

16 Aug 09:33:13 - [trace] [flow:7c8450cf.91f9] start flow [7c8450cf.91f9]
16 Aug 09:33:13 - [debug] [ha-entity:44178828.588e18] instantiated node, name: undefined
16 Aug 09:33:13 - [debug] [trigger-state:bfeb6b2b.d41298] instantiated node, name: undefined
16 Aug 09:33:13 - [debug] [api-call-service:Notify iOS] instantiated node, name: Notify iOS
TypeError: Cannot read properties of undefined (reading 'id')
    at /opt/node_modules/@node-red/runtime/lib/flows/Subflow.js:209:140
    at Array.map (<anonymous>)
    at /opt/node_modules/@node-red/runtime/lib/flows/Subflow.js:209:95
    at Array.map (<anonymous>)
    at Subflow.start (/opt/node_modules/@node-red/runtime/lib/flows/Subflow.js:209:62)
    at Flow.start (/opt/node_modules/@node-red/runtime/lib/flows/Flow.js:224:41)
    at start (/opt/node_modules/@node-red/runtime/lib/flows/index.js:394:33)
16 Aug 09:33:13 - [debug] [ha-entity:fa441d9e.1b4cc] instantiated node, name: undefined
16 Aug 09:33:13 - [debug] [api-call-service:Alphrad] instantiated node, name: Alphrad
16 Aug 09:33:13 - [debug] [inject:noon] crontab = 00 12 * * *
16 Aug 09:33:13 - [debug] [api-call-service:a723c6f5.a9c8e8] instantiated node, name: undefined
16 Aug 09:33:13 - [debug] [server-state-changed:4c8b149b.72ee6c] instantiated node, name: undefined
16 Aug 09:33:13 - [debug] [inject:17:00] crontab = 00 17 * * *
16 Aug 09:33:13 - [debug] [api-call-service:Notify iOS] instantiated node, name: Notify iOS
16 Aug 09:33:13 - [debug] [api-call-service:Notify iOS] instantiated node, name: Notify iOS
16 Aug 09:33:13 - [debug] [inject:4:00] crontab = 00 04 * * *
16 Aug 09:33:13 - [debug] [ha-entity:b1c6d402.e40af8] instantiated node, name: undefined

@knolleary added some trace logging. not sure if this is red herring.