Error is reported as:

java.lang.IllegalArgumentException: You are starting application with AOT mode but not AOT-processed, please build your application with AOT first. Or remove system property 'spring.aot.enabled=true' to run as regular mode.
    at org.springframework.boot.SpringApplication.addAotGeneratedInitializerIfNecessary(SpringApplication.java:441) ~[main/:?]
    at org.springframework.boot.SpringApplication.prepareContext(SpringApplication.java:396) ~[main/:?]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:322) ~[main/:?]

instead of:

java.lang.IllegalArgumentException: Could not find class [org.springframework.boot.SpringApplicationTests$TestSpringApplication__ApplicationContextInitializer]
    at org.springframework.util.ClassUtils.resolveClassName(ClassUtils.java:355) ~[spring-core-6.1.0-RC2.jar:6.1.0-RC2]
    at org.springframework.context.aot.AotApplicationContextInitializer.instantiateInitializer(AotApplicationContextInitializer.java:80) ~[spring-context-6.1.0-RC2.jar:6.1.0-RC2]
    at org.springframework.context.aot.AotApplicationContextInitializer.initialize(AotApplicationContextInitializer.java:71) ~[spring-context-6.1.0-RC2.jar:6.1.0-RC2]
    at org.springframework.context.aot.AotApplicationContextInitializer.lambda$forInitializerClasses$0(AotApplicationContextInitializer.java:61) ~[spring-context-6.1.0-RC2.jar:6.1.0-RC2]
    at org.springframework.boot.SpringApplication.applyInitializers(SpringApplication.java:623) ~[main/:?]
    at org.springframework.boot.SpringApplication.prepareContext(SpringApplication.java:397) ~[main/:?]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:322) ~[main/:?]
    ... 
Caused by: java.lang.ClassNotFoundException: org.springframework.boot.SpringApplicationTests$TestSpringApplication__ApplicationContextInitializer
    at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641) ~[?:?]
    at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:188) ~[?:?]
    at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:525) ~[?:?]
    at java.base/java.lang.Class.forName0(Native Method) ~[?:?]
    at java.base/java.lang.Class.forName(Class.java:467) ~[?:?]
    at org.springframework.util.ClassUtils.forName(ClassUtils.java:304) ~[spring-core-6.1.0-RC2.jar:6.1.0-RC2]
    at org.springframework.util.ClassUtils.resolveClassName(ClassUtils.java:345) ~[spring-core-6.1.0-RC2.jar:6.1.0-RC2]
    ... 

Comment From: mhalbritter

Thank you!