You did setup a NEW SDK with the B4A SDK Maanager?
You did used a Blank folder for the new SDK?
Or do you reused an old SDK-Folder???
In case you are reusing an old SDK-Folder:
The old sdk-Folder isn´t compatible anymore. Google has changed it. You need to setup a new SDK. You can find the Setup-Instructions here. https://www.b4x.com/b4a.html
You also can watch this Video as it describes clearly each step.
Start with a new Blank folder like you see in the Video.