See the reference GitHub project.
I've got an @Entity with a @Version'ed field, a @Projection, and a Repository. When I try to GET the projection of a single entry, I get a 500 Internal server error, because of a failed assertion in BasicPersistentEntity line 394, as called from Etag line 191:
> Assert.isTrue(getType().isInstance(bean), "Target bean is not of type of the persistent entity!");
The argument bean here is of type $Proxy90 / JdkDynamicAopProxy, not Book.
The projection only works again when the @Version annotation is removed. This is since Fowler, as I had no such issues with Evans.