If an interface that extends Serializable is defined, and a default method is written, then a hint to add a serialVersionUID may be displayed (if enabled). This is incorrect as a (private) serialVersionUID field cannot be defined in an interface. This does not occur on interfaces without default methods.

For example:

interface Blah extends java.io.Serializable {

  default int one() { return 1; }

}

The associated refactoring tries to modify this to the following, which does not compile:

interface Blah extends java.io.Serializable {

  private static final long serialVersionUID = 1L;

  default int one() { return 1; }

}