Question: project facet java version 1.8 is not supported in tomcat 8?
Answer: Go to Project Properties -> Project Facets -> Runtime -> New -> Add a tomcat server and in JRE select JRE1. 8.0_XX. That is because you just changed your JRE location in the workspace property, which TOMCAT relies on. ... Remove Tomcat 8.0 and add Tomcat v9.