Both CIQ datafields in the activity crash suddenly

No, no background, a Datafield that reads info in compute and draws directly to dc in onUpdate. This one I use every day for walks.

Another one is similar, and also uses ANT via GenericChannel. This is not used all the time but when it is there then both crash at the same time.

Yesterday I removed my datafields and added a random CIQ field from another developer. If it'll not crash in the next couple of days, then I'll blame it on a bug in at least one of my datafields, however on both of them I do get ERA reports from other devices, but 0 reports from me (I use them as beta app from the store)

jim_m_58 said:

omStop isn't called in DFs

What do you base this on?

In other threads you wrote not to read/write properties from onStop (not sure if it was regarding datafields or in general). And because I did see stack traces in ERA until a month ago that start from onStop, I'm 100% sure that this statement is false!

Error Name: Unhandled Exception
Occurrences: 1
First Occurrence: 2026-02-14
Last Occurrence: 2026-02-14
Devices:
Forerunner® 255: 27.09
App Versions: 2.6.1
Languages: eng
Backtrace:
MyDFApp.<globals/MyDFApp/<>releaseSensor>:147
MyDFApp.onStop:139

Actually I made changes in the recent version to move these property read/writes out of onStop (which seems to have worked: it either doesn't have the property related exceptions from onStop any more, or maybe since last month Garmin stopped calling onStop in datafields :) 

I don't recall when it happened with DFs - it's been years. I don't see anything in the doc, but I know I changed by DF's with a background service as a result.  Try it yourself with a sideload with a background service and println calls.

So again, what are you claiming? Not that onStop is not called in datafields, just that onStop is not called on the background process in datafields?

No, it's not called in the main app for a DF.

I found some old code I had to change for the temporal events would stop when they should.

function onTimerStart() {
System.println("start");
Background.registerForTemporalEvent(new Time.Duration(5 * 60));
}

function onTimerStop() {
System.println("stop");
Background.deleteTemporalEvent();
}

How do you explain this?

Error Name: Unhandled Exception
Occurrences: 1
First Occurrence: 2026-02-14
Last Occurrence: 2026-02-14
Devices:
    Forerunner® 255: 27.09
    vívoactive® 5: 17.05
App Versions: 2.6.1
Languages: eng
Backtrace:
    MyDFApp.<globals/MyDFApp/<>releaseSensor>:147
    MyDFApp.onStop:139

or this:

Error Name: Unhandled Exception
Occurrences: 62
First Occurrence: 2024-09-05
Last Occurrence: 2024-09-14
Devices:
    Forerunner® 955 / Solar: 19.18, 20.26
App Versions: 2.5.2
Languages: spa
Backtrace:
    MyDFApp.onStop:127

Maybe the above two is not from the main app. I don't have "background", but the 1st one can be the Sensor pairing flow (kind of background). The 2nd can't be, because in 2024 it wasn't available yet (certainly not in my datafield)

Or this, from another DF, that has nothing special:

Error Name: Unhandled Exception
Occurrences: 71
First Occurrence: 2025-09-28
Last Occurrence: 2026-01-04
Devices:
    Descent™ Mk3 43mm / Mk3i 43mm: 23.30, 22.11, 23.49, 22.07
App Versions: 1.9.5
Languages: cht
Backtrace:
    HikerDFApp.onStop:16
 

Ok, so after removing both of my DF-s from Walk I added GRun so I have some CIQ field. Yesterday I had no crash. Today in the morning I had no crash, and finished by "Resume later". 2 minutes ago, before I wanted to go to run I entered Walk to not continue but to save it. From the menu where I could choose Resume or Save I clicked Back to see the screen and just as I entered it crashed the CIQ field with IQ...

So this is deffinitely not an issue with my CIQ fields. It's something to do with the fr965 firmware.

Is "resume later" involved when your DFs crash?  It's always been a bit tricky with CIQ

Maybe I'm not alone: https://www.reddit.com/r/strydrunning/s/fyLR5mF6KL