Matrix Error. Invalid dimension size: 0

[Woodtip]

Hi, Can someone please help.

After some significant updates to a long established app, I am getting the following error via a notifier: Matrix Error. Invalid dimension size: 0

It is not on any of the new code. I have regressed the app to a version before I made any changes and it now has the same issue, but apps of the same version currently in use by other users do not have the issue. There is no error when linked to the Companion app, only when compiled, built and installed which leads me to think it might be platform related?
I think it is happening when storing a variable that is a list to TDB, something that I have used for several years with no issue.

Thanks in advance.

[ABG]

Matrices were introduced in a recent AI2 version, 2.78

Download and install the new Companion, then try again.

If you still get that error, export and upload your aia here

[DTODO_INVENTARIOS]

Yesterday 17/03/2026I was working on my app, I exported the AIA and APK files and installed them on my phone, and they worked correctly. However, when I tried to create another APK from the same app without changing any blocks, this app gives me an error on startup. Did something change on the page? Or was there some kind of update?

[ABG]

Please export and upload here your aia file.

The new release of AI2 yesterday requires an updated Companion.

Problems with built apps, however, require an aia for us to test.

[Woodtip]

Hi, thanks for your reply. I updated the companion and I now get the error both when using the companion and from the installed APK. It is definitely to do with TinyDB and Store/Get empty lists. TinyDB used to Store / Get empty lists no problem, but now it shows this error.

[Woodtip]

Hi, yes, this is what has happened to me. For my app, it is to do with TinyDB storing and getting empty lists which used to work fine.

[Woodtip]

Hi again. I can’t put my app into the forum but this is the issue…a couple of days ago, this worked fine. Now it shows the error ‘Invalid dimension size: 0’

[TIMAI2]

I can confirm this behaviour (with companion app).

[DTODO_INVENTARIOS]

[davidefa]

It’s working ok here ( on companion 2.77u )

P.S.

Strangely minutes ago the same aia returned an error ( wrong number of parameters in notifier )

db01.aia (1.9 KB)

[TIMAI2]

@davidefa

on companion 2.77u

You haven't updated your companion app.

[Heber_Alberto_Rosas]

I also need to save empty lists in tinydb, somebody knows if app inventor are gonna fix it? or this is the way it works now?

Thanks

[ABG]

Any ideas, @jackyc-11 ?

[All_In_One1]

I am also facing same problem (Matrix Error.Invalid dimension size: 0). Moreover there is another problem . The variable that I have created is automatically changed in block section. Such as

Set Episode_number = 1, it became Set Database_pic = 1

It is very difficult to find out the changed and fix it. This is happening from yesterday after the updates cz I am already used the apk which I built on Tuesday .

[ABG]

@All_In_One1

I am also facing same problem

ABG Power User

9h

Matrices were introduced in a recent AI2 version, 2.78

Download and install the new Companion, then try again.

If you still get that error, export and upload your aia here

[Walberto_Marrugo]

Tengo el mismo error con una aplicacion que llevo 5 años refactorizando y ahora cualquier versiuon que pruebo me retorna error dimension size

[Woodtip]

Hi,

could you please confirm whether this is being worked on and a possible resolution timescale.
Thank you.

[ewpatton]

I'm going to take a look at it today.

[ABG]

It would be very interesting to see the different ways lists and matrices are represented in the TinyDB XML file back ends, and how they are distinguished.

[Anke]

@ABG

It would be very interesting to see the different ways lists and matrices are represented in the TinyDB XML file back ends