After updating from Spring Boot 2.1.0.RELEASE to 2.1.1.RELEASE, all HTTPS requests fail with the following error:
2018-12-03 14:23:46,089 PID=21726 LEVEL=ERR
Spring Boot 2.1.1 upgraded to Tomcat 9.0.13 from 9.0.12. Due to this change, Tomcat 9.0.13 requires a version of Tomcat Native that contains this change. It is available in 1.2.18 and later. The requirement to use a new patch release of Tomcat Native when upgrading to a new patch release of Tomcat is to be expected. Similarly, it is also to be expected that a new patch release of Spring Boot will update to a new patch release of one of its dependencies.
If your OS does not provide an up-to-date Tomcat Native package that you can use, I would recommend building it yourself. Instructions for doing so can be found in Tomcat's documentation. This is preferable to downgrading Tomcat to 9.0.12 as getting stuck on an older version increases your risk of being affected by a bug or security vulnerability in the future.