For some time now this test didn't work properly on RHEL6:
https://github.com/jbosstools/jbosstools-server/tree/master/as/itests/org.jboss.tools.as.ui.bot.itests

Today I investigated a bit and found out that there's this annoying dialog window popping up asking if you want to use html5 or xulrunner for VPE. This happens when a jsp file from a test project is being created and opened.