Matrix Error. Invalid dimension size: 0

ABG · March 19, 2026, 5:10pm

Given the lack of any type metadata for the TinyDB values in the XML, types must be determined by guesswork.

I can easily imagine a matrix implementor giving precedence to their favored data type (matrices) when retrieving from TinyDB, and imposing matrix validation for the intersectional case of empty lists.

Assigning a matrix data type (in the lack of metadata) should be done only in the most stringent of circumstances (at least 1 row, each row a list of identical lengths), leaving the rest of the values as lists or whatever JSON says.

ewpatton · March 19, 2026, 6:43pm

Yes that is pretty much what happened and I'm working on the fix.

Heber_Alberto_Rosas · March 19, 2026, 7:09pm

Thank you

ewpatton · March 19, 2026, 7:24pm

We have a solution and will be putting the fix up on ai2-test later today.

Woodtip · March 19, 2026, 7:32pm

That’s fantastic. Thank you very much.

ewpatton · March 19, 2026, 9:51pm

The proposed fix is now on ai2-test.appinventor.mit.edu. It requires loading the test companion from that server and/or compiling your apps there until we push it to the production servers.

ABG · March 19, 2026, 11:10pm

Tests okay on ai2-test with the updated Companion 2.78t1u and built apk.

TinyDB_empty_list_matrix_test.aia (3.0 KB)

All_In_One1 · March 20, 2026, 4:22am

Sir,

Has anything else changed on ai2-test? Cz I am not able to compile the apk. It shows “Build failed! [RunD8] ERROR: d8 failed.”. On the other hand I can compile same aia on main builder but faceing matrix error.

Woodtip · March 20, 2026, 9:07am

Hi,

I am getting the same as this.

Woodtip · March 20, 2026, 9:11am

Hi,
this has fixed the error for me when using the test companion but the app will not compile due to a RunD8 ERROR.

Nicola_Imperati · March 20, 2026, 11:31am

Hi,
I tried to compile my app from your server, but I get this error:

App Inventor is unable to compile this project.
The compiler error output was
[ReadBuildInfo] Starting Task
[ReadBuildInfo] Task succeeded in 0.005 seconds
[LoadComponentInfo] Starting Task
[LoadComponentInfo] INFO: Generating assets...
[LoadComponentInfo] Component assets needed, n = 0
[LoadComponentInfo] INFO: Generating activities...
[LoadComponentInfo] Component activities needed, n = 0
[LoadComponentInfo] Component activity metadata needed, n = 0
[LoadComponentInfo] INFO: Generating broadcast receivers...
[LoadComponentInfo] INFO: Generating libraries...
[LoadComponentInfo] Libraries needed, n = 5
[LoadComponentInfo] Component metadata needed, n = 0
[LoadComponentInfo] INFO: Generating Android minimum SDK...
[LoadComponentInfo] INFO: Generating native libraries...
[LoadComponentInfo] Native Libraries needed, n = 0
[LoadComponentInfo] INFO: Generating permissions...
[LoadComponentInfo] usesLocation = false
[LoadComponentInfo] Permissions needed, n = 6
[LoadComponentInfo] Component xmls needed, n = 0
[LoadComponentInfo] Component features needed, n = 0
[LoadComponentInfo] INFO: Generating component broadcast receivers...
[LoadComponentInfo] Task succeeded in 0.019 seconds
[PrepareAppIcon] Starting Task
[PrepareAppIcon] INFO: Creating mipmap dirs...
[PrepareAppIcon] INFO: Generating icons...
[PrepareAppIcon] Generating icons for mipmap-mdpi
[PrepareAppIcon] Generating icons for mipmap-hdpi
[PrepareAppIcon] Generating icons for mipmap-xhdpi
[PrepareAppIcon] Generating icons for mipmap-xxhdpi
[PrepareAppIcon] Generating icons for mipmap-xxxhdpi
[PrepareAppIcon] Task succeeded in 0.322 seconds
[XmlConfig] Starting Task
[XmlConfig] INFO: Creating animation xml
[XmlConfig] Creating zoom_enter.xml
[XmlConfig] Creating fadeout.xml
[XmlConfig] Creating slide_v_exit.xml
[XmlConfig] Creating fadein.xml
[XmlConfig] Creating zoom_exit.xml
[XmlConfig] Creating slide_v_enter.xml
[XmlConfig] Creating zoom_exit_reverse.xml
[XmlConfig] Creating slide_v_enter_reverse.xml
[XmlConfig] Creating zoom_enter_reverse.xml
[XmlConfig] Creating slide_enter_reverse.xml
[XmlConfig] Creating slide_exit.xml
[XmlConfig] Creating hold.xml
[XmlConfig] Creating slide_enter.xml
[XmlConfig] Creating slide_v_exit_reverse.xml
[XmlConfig] Creating slide_exit_reverse.xml
[XmlConfig] INFO: Creating style xml
[XmlConfig] INFO: Creating provider_path xml
[XmlConfig] INFO: Creating network_security_config xml
[XmlConfig] INFO: Generating adaptive icon file
[XmlConfig] INFO: Generating round adaptive icon file
[XmlConfig] INFO: Generating adaptive icon background file
[XmlConfig] Task succeeded in 0.005 seconds
[CreateManifest] Starting Task
[CreateManifest] INFO: Reading project specs...
[CreateManifest] VCode: 1
[CreateManifest] VName: 1.0
[CreateManifest] Min SDK 14
[CreateManifest] INFO: Writing screen 'appinventor.ai_nicolaimperati1978.MyFrigo2.Screen1'
[CreateManifest] INFO: Writing screen 'appinventor.ai_nicolaimperati1978.MyFrigo2.DietaMaria'
[CreateManifest] Task succeeded in 0.001 seconds
[AttachNativeLibs] Starting Task
[AttachNativeLibs] Task succeeded in 0.001 seconds
[AttachAarLibs] Starting Task
[AttachAarLibs] Task succeeded in 0.228 seconds
[AttachCompAssets] Starting Task
[AttachCompAssets] Task succeeded in 0.018 seconds
[MergeResources] Starting Task
[MergeResources] Task succeeded in 0.306 seconds
[SetupLibs] Starting Task
[SetupLibs] Task succeeded in 0.0 seconds
[RunAapt] Starting Task
[RunAapt] Task succeeded in 1.076 seconds
[GenerateClasses] Starting Task
[GenerateClasses] INFO: Source File: appinventor/ai_nicolaimperati1978/MyFrigo2/Screen1.yail
[GenerateClasses] INFO: Source File: appinventor/ai_nicolaimperati1978/MyFrigo2/DietaMaria.yail
[GenerateClasses] INFO: Libraries Classpath = /tmp/kawa1887518891783700878.jar:/tmp/acra-4.4.011283673220057778254.jar:/tmp/AndroidRuntime5553066230744149609.jar:/tmp/annotation7772046011322708261.jar:/tmp/annotation-experimental14143208388361824139.jar:/tmp/appcompat15341999738487119629.jar:/tmp/asynclayoutinflater16972871168254571442.jar:/tmp/collection26227856196477867.jar:/tmp/constraintlayout13180948948224755581.jar:/tmp/constraintlayout-solver7005042410733194649.jar:/tmp/coordinatorlayout7786045738133783735.jar:/tmp/core3395307230718333154.jar:/tmp/core-common12846637348411052662.jar:/tmp/core-runtime16327148525277501808.jar:/tmp/cursoradapter17972244707497914334.jar:/tmp/customview14548494377990759654.jar:/tmp/documentfile18050605573432216302.jar:/tmp/drawerlayout8478401829615826751.jar:/tmp/fragment3071877605334657380.jar:/tmp/interpolator13824350421968939963.jar:/tmp/legacy-support-core-ui10818548148380966558.jar:/tmp/legacy-support-core-utils14528070247693580284.jar:/tmp/lifecycle-common4328242107302688970.jar:/tmp/lifecycle-livedata8422463421640428527.jar:/tmp/lifecycle-livedata-core1988334565326521940.jar:/tmp/lifecycle-runtime1300149025978877355.jar:/tmp/lifecycle-viewmodel9968984344714865670.jar:/tmp/loader11983121691446382364.jar:/tmp/localbroadcastmanager7561620440467156030.jar:/tmp/print8168696041590115493.jar:/tmp/slidingpanelayout17791436109412769631.jar:/tmp/swiperefreshlayout13670269000162923765.jar:/tmp/vectordrawable13576350722447939399.jar:/tmp/vectordrawable-animated11219099279816848793.jar:/tmp/versionedparcelable8189301398841677764.jar:/tmp/viewpager7895202116450377568.jar:/tmp/recyclerview13266030522982332988.jar:/tmp/cardview10166338968723038616.jar:/tmp/dynamicanimation10426153727914610313.jar:/tmp/1774006089769_972618086808688640-0/youngandroidproject/../build/classes:/tmp/android16399370399525464649.jar
(compiling appinventor/ai_nicolaimperati1978/MyFrigo2/Screen1.yail to appinventor.ai_nicolaimperati1978.MyFrigo2.Screen1)
(compiling appinventor/ai_nicolaimperati1978/MyFrigo2/DietaMaria.yail to appinventor.ai_nicolaimperati1978.MyFrigo2.DietaMaria)
(compiling /tmp/runtime15269426166859534374.scm to com.google.youngandroid.runtime)
[GenerateClasses] Task succeeded in 5.207 seconds
[RunD8] Starting Task
[RunD8] INFO: Using pre-dexed dex-cached-0eb34064deeda81537ba9d997a688070.dex <- /tmp/AndroidRuntime5553066230744149609.jar
[RunD8] INFO: Using pre-dexed dex-cached-4afd1465d334dee94ac700edb0374a45.dex <- /tmp/kawa1887518891783700878.jar
[RunD8] INFO: Using pre-dexed dex-cached-558104d32e109ad96655ecbe9fe4e39f.dex <- /tmp/annotation7772046011322708261.jar
[RunD8] INFO: Using pre-dexed dex-cached-ef239d31d31d166f7410d71e14db1a68.dex <- /tmp/swiperefreshlayout13670269000162923765.jar
[RunD8] INFO: Using pre-dexed dex-cached-de87276390f7a8c71064f3e7908c143b.dex <- /tmp/core-common12846637348411052662.jar
[RunD8] INFO: Using pre-dexed dex-cached-c950a9845cca4523f19bc2fc922b41bf.dex <- /tmp/legacy-support-core-utils14528070247693580284.jar
[RunD8] INFO: Using pre-dexed dex-cached-35076b6f638faca00c217e98a0385344.dex <- /tmp/interpolator13824350421968939963.jar
[RunD8] INFO: Using pre-dexed dex-cached-bee920fd1e059913bf2d820dbb234720.dex <- /tmp/lifecycle-common4328242107302688970.jar
[RunD8] INFO: Using pre-dexed dex-cached-1e4d689047e2ee2cc76b7203626e9c33.dex <- /tmp/customview14548494377990759654.jar
[RunD8] INFO: Using pre-dexed dex-cached-74360288e1016af9d6afdd39a2caa1b8.dex <- /tmp/asynclayoutinflater16972871168254571442.jar
[RunD8] INFO: Using pre-dexed dex-cached-d53c4c8eedbf41663110b03a33fe9914.dex <- /tmp/lifecycle-runtime1300149025978877355.jar
[RunD8] INFO: Using pre-dexed dex-cached-032c68a2c5e93c1baac1524e105bbe88.dex <- /tmp/collection26227856196477867.jar
[RunD8] INFO: Using pre-dexed dex-cached-91b7d1f3cb5fd0fd2f3a4c939316139b.dex <- /tmp/versionedparcelable8189301398841677764.jar
[RunD8] INFO: Using pre-dexed dex-cached-16ea1fc3b7e49139559eafccec2708ab.dex <- /tmp/lifecycle-viewmodel9968984344714865670.jar
[RunD8] INFO: Using pre-dexed dex-cached-84637f838557e65ad5856467fd22316c.dex <- /tmp/print8168696041590115493.jar
[RunD8] INFO: Using pre-dexed dex-cached-a9e803bf51318b35fcaf603f59f25f7c.dex <- /tmp/vectordrawable13576350722447939399.jar
[RunD8] INFO: Using pre-dexed dex-cached-b73957ec00af79319f56aedf27dff3fc.dex <- /tmp/core-runtime16327148525277501808.jar
[RunD8] INFO: Using pre-dexed dex-cached-4e788f5c66d33a47036ae77a849ffa1b.dex <- /tmp/core3395307230718333154.jar
[RunD8] INFO: Using pre-dexed dex-cached-e890ce7827a13b8714afbb241f7e89b2.dex <- /tmp/lifecycle-livedata-core1988334565326521940.jar
[RunD8] INFO: Using pre-dexed dex-cached-9e7da29c234333f4d245d8baa48e1746.dex <- /tmp/annotation-experimental14143208388361824139.jar
[RunD8] INFO: Using pre-dexed dex-cached-81757b9148a3984b5874ef1fd300acdb.dex <- /tmp/documentfile18050605573432216302.jar
[RunD8] INFO: Using pre-dexed dex-cached-b83403f2b639cc6e7a6f9c0681d69367.dex <- /tmp/viewpager7895202116450377568.jar
[RunD8] INFO: Using pre-dexed dex-cached-c2a16bb02f51a6fcd1ff46dd1a78d0bf.dex <- /tmp/slidingpanelayout17791436109412769631.jar
[RunD8] INFO: Using pre-dexed dex-cached-2eabb48fdf784357d984acbda18ea6a3.dex <- /tmp/appcompat15341999738487119629.jar
[RunD8] INFO: Using pre-dexed dex-cached-7a5a85c38b934be86a121ca9b5e7477b.dex <- /tmp/vectordrawable-animated11219099279816848793.jar
[RunD8] INFO: Using pre-dexed dex-cached-a3a712d1d179d231b40a977ed5593202.dex <- /tmp/lifecycle-livedata8422463421640428527.jar
[RunD8] INFO: Using pre-dexed dex-cached-9b1768a7734de4eaf5a635a007ad4b25.dex <- /tmp/coordinatorlayout7786045738133783735.jar
[RunD8] INFO: Using pre-dexed dex-cached-d3d338969c3cd4ad53a888753da3b580.dex <- /tmp/cursoradapter17972244707497914334.jar
[RunD8] INFO: Using pre-dexed dex-cached-a116e0a41475b6522ae295f7cc4ff4b3.dex <- /tmp/legacy-support-core-ui10818548148380966558.jar
[RunD8] INFO: Using pre-dexed dex-cached-a07a23b88daaae0b48cdd25378e03b03.dex <- /tmp/localbroadcastmanager7561620440467156030.jar
[RunD8] INFO: Using pre-dexed dex-cached-bb8901219e7be6c576cc65e75503d7fa.dex <- /tmp/fragment3071877605334657380.jar
[RunD8] INFO: Using pre-dexed dex-cached-fca718e99e97cb52f4c8c0ada2c74e72.dex <- /tmp/drawerlayout8478401829615826751.jar
[RunD8] INFO: Using pre-dexed dex-cached-ccb6f0c5e0adc11059c3d609a2fd15d6.dex <- /tmp/loader11983121691446382364.jar
[RunD8] INFO: Using pre-dexed dex-cached-c0e4dda29672c028ea3ce0e3785040de.dex <- /tmp/constraintlayout13180948948224755581.jar
[RunD8] INFO: Using pre-dexed dex-cached-85f46a2fd295a23f59a391cccd7a11c8.dex <- /tmp/constraintlayout-solver7005042410733194649.jar
[RunD8] INFO: Using pre-dexed dex-cached-ae0a0504ff198c23ba89f60cba6bee1b.dex <- /tmp/dynamicanimation10426153727914610313.jar
[RunD8] INFO: Using pre-dexed dex-cached-742155d268fadbad92adb35be882bd67.dex <- /tmp/recyclerview13266030522982332988.jar
[RunD8] INFO: Using pre-dexed dex-cached-1bc51353c62ddc7fef531c4bbfd9e480.dex <- /tmp/cardview10166338968723038616.jar
[RunD8] ERROR: d8 failed.
[RunD8] Task errored in 1.035 seconds

ewpatton · March 20, 2026, 12:32pm

We run all of the libraries through d8 first in order to speed up subsequent builds, but the process seemed to get stuck. We've flushed the dex cache and builds should be working now.

Martin_Herraiz · March 21, 2026, 10:01am

I have a similar error when starting mi app:
Error 909 com.google.appinventor.components.runtime.errors.YailRuntimeError: Invalid dimension size: 0

TIMAI2 · March 21, 2026, 10:02am

Is fixed in ai2-test server, and will be coming in update release.

Martin_Herraiz · March 21, 2026, 3:25pm

In the test server, the problem is different.
When trying to install the app, it says: “La aplicación no se ha instalado por un conflicto con un paquete”

TIMAI2 · March 21, 2026, 3:33pm

The application could not be installed due to a conflict with a package.

You will need to uninstall your existing app, then install the new one created on ai2-test.

Anke · March 22, 2026, 6:11am

Or export the keystore from the main server and import it onto the test server (after backing it up from the test server).

Woodtip · March 23, 2026, 9:18am

Hi Anke.
I just wanted to check my understanding of your statement. Does this mean I can export the keystore from where I normally work on the app, import it into the test server and then compile the app in the test server and the resulting apk will then be accepted by the Play Store as if I had compiled it in my normal account?
Thanks.

Anke · March 23, 2026, 9:34am

Yes.

Woodtip · March 23, 2026, 1:53pm

Great, thank you.