I have a Java EE project which build fine with Ant, deploys perfectly to JBoss, and runs without any trouble. This project includes a few custom tag librari
I had the same problem with STS (springtool source suite).
Under STS, right click on the project, than "Properties", "Project Facets", than on the right of the window click on the "runtime" tab, and check "VMware vFabric tc Server (...)", and click "Apply" and it should be OK after the workspace refresh.