This exception may be caused by `hot deployment` tools (`spring-boot-devtool`) or otherwise, which changes the `classloader` in runtime.
### Resolution
1. This error does not occur under the production environment, since developer tools are automatically disabled: See [spring-boot-devtools](https://docs.spring.io/spring-boot/docs/current/reference/html/using-boot-devtools.html).
1. This error does not occur under the production environment, since developer tools are automatically disabled: See [spring-boot-devtools](https://docs.spring.io/spring-boot/docs/2.4.x/reference/html/using-spring-boot.html#using-boot-devtools).
2. If you would like to debug in your development environment as usual, you should temporarily remove such `hot deployment` package in your lib path.