javac error: Class names are only accepted if annotation processing is explicitly requested

This error message indicates that you are trying to use a class name in a source code file that is not being processed by the Java compiler.

There are a few potential causes for this error:

1. You may be trying to use a class name as a variable name or in some other context where it is not allowed. Make sure that you are not using a class name where a variable or function name is expected.

2. You may be trying to use a class name that is not in your classpath. Make sure that the class you are trying to use is properly imported or that its fully qualified name is used.

3. You may have forgotten to enable annotation processing. Annotation processing is a feature of the Java compiler that allows you to generate additional source code or resources based on annotations in your source code. If you are using annotations and have not explicitly enabled annotation processing, you will see this error. To enable annotation processing, you can use the -processor command line option or the apt tool.

I hope this helps! Let me know if you have any questions or if you need further assistance.