Both SecurityFilterAutoConfiguration and SessionRepositoryFilterConfiguration use EnumSet::copyOf in a stream. If the stream ends up being empty then the copyOf method will throw an exception.

Comment From: DogeC0in

I find that SessionProperties.Servlet#setFilterDispatcherType(Set filterDispatcherTypes),when filterDispatcherTypes have a null element，the bug will be reproduce.So,what do I think filterDispatcherTypes have empty element or not there?

Comment From: wilkinsona

Closing in favour of https://github.com/spring-projects/spring-boot/pull/22138.