Unable to serialize app data - Watch App

I recently started to get the following error in the Debug Console in Visual Studio Code, "Unable to serialize app data".

The error occurs when I run the simulator and then File->Edit Persistent Storage->Edit Application.Properties Data, to change the settings.

When the error occurs I am unable to change the watch settings, I have to delete the App, reset everything for the simulator and then everything is okay.

When I deploy the Watch App, my Garmin Epix Pro 2 and Venu watches seem to function okay and without error.

My concern is that this just started to happen and I cannot work out why, and may be symptomatic of an issue that may cause problems.

I'm using SDK 8.1.1, and between the time when the error didn't occur and started to occur I did not change the SDK.

Does anyone know what causes this, or has also experienced this issue?

Top Replies

SimonJEdwards 11 days ago in reply to FlowState +1

i removed all Background permissions, and then rebuilt and tested on my Epix Pro 2 and Venu and everything works without it!

All Replies

0 jim_m_58 12 days ago in reply to SimonJEdwards

Yes, you really need to learn to use the (:background) annotation.

See https://developer.garmin.com/connect-iq/connect-iq-faq/how-do-i-create-a-connect-iq-background-service/#howdoicreateaconnectiqbackgroundservice

Aldo here is a thread about a very simple watch face with a background do you can see how it's used: https://forums.garmin.com/developer/connect-iq/f/discussion/5287/very-simple-sample-of-a-watch-face-with-a-background-process

0 SimonJEdwards 12 days ago in reply to jim_m_58

Is there any reason that Watch Face needs Background Permissions? Or should it generally be not be enable. I have had it enabled, and so get the warning the whole app will be loaded as Background.

0 _psx_ 12 days ago in reply to SimonJEdwards

Can you clarify, do you build watch app, widget or watch face? You still use "Watch App" but screen shows memory for watch face...

Why do you use background? You should use it in some situation that require the background app (and yes, permission is required then) but it isn't an obligation!

0 SimonJEdwards 12 days ago in reply to _psx_

I build Watch Faces apps.garmin.com/.../47dc5efa-bc7c-43a2-a6f6-bbaa306fd778

0 FlowState 12 days ago in reply to _psx_

_psx_ said:
Can you clarify, do you build watch app, widget or watch face? You still use "Watch App" but screen shows memory for watch face...

It was probably a mistake for Garmin to create app types called "watch app" and "watch face". As with Connect and Connect IQ, confusion seems inevitable and inescapable.

Even better, in other contexts, instead of "watch app", Garmin says "Device App" or "App".

"What kind of CIQ app is this?"

"It's an app."

"What *kind* of app?"

"An *app*".

it's not as if the "device" and "watch" modifiers really add anything to the meaning of "app" though. Every other app type - like widget, watch face, and music provider - is also intended run on a "watch" or other type of Garmin "device".

Same issue with having a specific model of MacBook called MacBook, and a specific model of iPad called iPad.

0 FlowState 12 days ago in reply to SimonJEdwards

SimonJEdwards said:
Is there any reason that Watch Face needs Background Permissions? Or should it generally be not be enable. I have had it enabled, and so get the warning the whole app will be loaded as Background.

If you don't know why your app needs background permissions, it's probably safe to say it doesn't need them.

Alternatively, if you remove background permissions and a new compile-time or run-time error pops up, you'll have your answer.

0 _psx_ 11 days ago in reply to SimonJEdwards

So you probably use buffered bitmap and probably you have the 2 buffered bitmap in one moment after changing e.g. colors. So first set null to the old member.

And watched with graphics pool can another problem - the limit of memory of the graphic pool, the 3rd place with potential out of memory exception.

Remove background permission and you will see compilation error so will find out why you use it.

0 SimonJEdwards 11 days ago in reply to FlowState

i removed all Background permissions, and then rebuilt and tested on my Epix Pro 2 and Venu and everything works without it!