When trying to accept Android Studio licenses, I keep getting this error "java.lang.NoClassDefFoundError"

I am trying to build my first android studio project. I keep getting this error:

Exception in thread "main" java.lang.NoClassDefFoundError: javax/xml/bind/annotation/XmlSchema

When I try to build the simplest "MyFirstApp" project, I do not get this error.

I have tried to run the sdkmanager from the terminal:

cd /Users/username/Library/Android/sdk/tools/bin
./sdkmanager --licenses

as well as by physically going to the sdkmanager directory, and double clicking on sdkmanager.

I get the same error on both. I also updated my Java. So, why do I get this error? And how do I fix it?

The full error is as follows:

Exception in thread "main" java.lang.NoClassDefFoundError: javax/xml/bind/annotation/XmlSchema
    at com.android.repository.api.SchemaModule$SchemaModuleVersion.<init>(SchemaModule.java:156)
    at com.android.repository.api.SchemaModule.<init>(SchemaModule.java:75)
    at com.android.sdklib.repository.AndroidSdkHandler.<clinit>(AndroidSdkHandler.java:81)
    at com.android.sdklib.tool.sdkmanager.SdkManagerCli.main(SdkManagerCli.java:73)
    at com.android.sdklib.tool.sdkmanager.SdkManagerCli.main(SdkManagerCli.java:48)
Caused by: java.lang.ClassNotFoundException: javax.xml.bind.annotation.XmlSchema
    at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:602)
    at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178)
    at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521)
    ... 5 more

Also, just adding it here, in case it is relevant, this is the output I get when running java --version:

java 13.0.2 2020-01-14
Java(TM) SE Runtime Environment (build 13.0.2+8)
Java HotSpot(TM) 64-Bit Server VM (build 13.0.2+8, mixed mode, sharing)

I checked the gradle sync inside Android Studio itself, and I found there was another error there:

ERROR: Module 'app': platform 'android-29' not found.

This was probably because I had downloaded the latest Android version, which is Android R (aka Android 30 in Android Studio), while this project probably expected version 29 (Android Q). So, once I downloaded and installed Android 29, by going to Tools -> SDK Manager, and restarted Android Studio, it works fine and does not give any error.