Live testing not working


Ok that was it; the debugging mode.
But unfortunatly after the app starts, I get the same picture as on the start of my request. See first entry…
I’m working with a test device samsung s 7, android version 7.0
Meanwhile I have 4700 blocks…


Sorry, but some idea?


The thread subject is “Live testing not working”. Maybe a new thread should be opened because you mentioned that you can connect for testing.


? What does that mean?


For your other apps, can you perform Live Testing? If yes, then we can open up a new thread specific to your scenario ( 4700 blocks) and continue conversation / diagnosis in that thread.


well, as @Italo already suggested…

see also tip 3 here

btw. if 4200 blocks do not work anymore, does it makes sense to add more blocks? Not really…


Meanwhile I have 4800 blocks.
When I build the apk everything is perfect and also running perfect …
It’s just somehow a huge app… working perfect - but just as apk - on my device


If your app works as an apk but not in the companion, you might take that as a signal that you are getting closer to the limits. AppyBuilder / App Inventor has limitations. They are not meant to create huge professional apps like, for example MyFitnessPal, Facebook, etc.

Although you can make very professional and well polished apps with these platforms, the amount of resources are rather limited compared to a platform like Android Studio.

if your app needs to keep growing, please have these limitations in mind.

With that said, most of the times, when checking the layout/blocks of an app, we find ways to optimize tasks into common procedures, groups of blocks that are not really necessary, files forgotten in the assets folder that are not used, or others that are too big for what you need them for, unnecessary visual effects, splash screens, hidden debug labels, etc.

And how about extensions? Do you have some extensions loaded in your project? Are they all compatible between each other? How big are those?

Ultimately you will have to sit one day with a lot of time and patience and go thru the whole project, deciding if you still need this or that part, if you can optimize a process, if there’s a better way to do something, etc, etc, etc.


Can you tell me, what the limitations are?

  1. How many blocks?
  2. How many procedures?
  3. How many variables?
  4. How many clocks and so on…
    Where can I read something about it?

Thanks so far.


Now I found out what the problem for that is:
I deleted many componets, canvases, arrangements and so on. But the problem is


When I use this “Microbit_Uart”-extension then at the start up of the app shows the above images as written a month ago.
So what could I do? Is there something else that I can use to get data writen form the micro:bit?


So now, some more infos about micro:bit extension.
I don’t know who wrote the extension, but from the moment you use one element of the extensions shown in the picture, LIVE TESTING is no longer working. Does anyone have a suggestion for a workraund?



@WebAtelier_mt checkout your extension download site. It may include information about developer.


It’s Evan P. from micro:bit, I think. I’ll try to get in contact with him.


I adjusted and changed the code, so that it works with app inventor 2. Everything works fine.
So, there must be an error in appybuilder. Please check and try to fix it.

Thanks so far.


@WebAtelier_mt please pm me your code so that we can check into it


Hi Hossein,
thanks, I attached the code…

BluetoothConnection.aia (803,5 KB)


As you can see, when you remove the extensions from micro:bit everything in “live testing” works, but a s soon as you use one of them “live testing” hangs in appybuilder…


We’ll check to see if we can find the issue


@WebAtelier_mt I tried your source on MIT AI2 and it can’t connect to their companion.


For me it works. It’s just an test app to see if I have something else as only the empty buttons on the screen.
Of course the app is looking for the sensor but this isn’t important at the moment.
If you just see the lables “Temperatur” and “LED-Text”, everything is fine.
Sorry, I sent you the version with the two tinyy db’s: This, of course only works withyour appybuilder.
If you please, just remove the block “SetDBPlayer.DatabaseName” and the textblock beside, then it works.