Android Question Get error after Updating B4X

[Olli73]

Hello,
after updating to B4X with Version 12.80 I have problems to update an old project.

I get the error message: java.lang.NoClassDefFoundError: Failed resolution of: Landroidx/viewpager/widget/ViewPager$OnPageChangeListener;
when I tried the app with an old device with Android 12.
I use in the manifest: <uses-sdk android:minSdkVersion="21" android:targetSdkVersion="26"/>

I changed the targetSdkVersion to other values. But all together, I cannot manage this problem....
How can I fix it?
Olli

 

[Sagenut]

From which previous version of B4X did you updated?
If you came from a version older than 12.50 then you need a new Android SDK folder.
You can find everything in the B4A installation page.
Follow carefully all the steps and download the new parts.

 

[Olli73]

The app is made with B4A 9.90. But I installed the B4X V 12.9 on a new laptop.... Before I installed only a Version of AndroidStudio...
I installed the sdk by Android Studio/ SDK Manager. This is the path to the sdk, I use in B4X: C:\Users\Olli\AppData\Local\Android\Sdk\platforms\android-34\android.jar

 

[Sagenut]

You need to download the Android SDK from the B4A installation page.
Do not share the Android Studio SDK.

 

[Sagenut]

Everything you need it's here
https://www.b4x.com/b4a.html
Follow all the steps.

 

[Olli73]

Ok, I did it and install the sdk command line tools and the ressources.... how can I accept the license? If i print: sdkmanager.bat --licenses I got the error, "Could not determine sdk root"

 

[Sagenut]

No need to do anything.
You must just be sure to read and understand the license.

 

[Olli73]

Thanks a lot... I solved it now... The app was launching for a short moment. Acctually I had to change the firebase Messaging code to the new one and have to change an old code fragment with notification builder.... both were the reasons for my trouble after updating....