Spring Boot file upload, Download Issue solution - How to resolve 500 internal server and 400 issue

Errors occurred during the build.
Errors running builder 'Java Builder' on project 'demo'.
Unable to make protected final java.lang.Class java.lang.ClassLoader.defineClass(java.lang.String,byte[],int,int) throws java.lang.ClassFormatError accessible: module java.base does not "opens java.lang" to unnamed module @5de5e95 how solve this problem

Bing reward me error 500ka batao yr dimag kharab h bhut