Error logged from Debug UI: 
org.eclipse.core.runtime.CoreException: Plug-in org.jboss.ide.eclipse.freemarker was unable to load class org.jboss.ide.eclipse.freemarker.linetracker.ConsoleLineTracker.
	at org.eclipse.core.internal.registry.osgi.RegistryStrategyOSGI.throwException(RegistryStrategyOSGI.java:194)
	at org.eclipse.core.internal.registry.osgi.RegistryStrategyOSGI.createExecutableExtension(RegistryStrategyOSGI.java:176)
	at org.eclipse.core.internal.registry.ExtensionRegistry.createExecutableExtension(ExtensionRegistry.java:905)
	at org.eclipse.core.internal.registry.ConfigurationElement.createExecutableExtension(ConfigurationElement.java:243)
	at org.eclipse.core.internal.registry.ConfigurationElementHandle.createExecutableExtension(ConfigurationElementHandle.java:55)
	at org.eclipse.debug.internal.ui.views.console.ProcessConsoleManager.getLineTrackers(ProcessConsoleManager.java:281)
	at org.eclipse.debug.internal.ui.views.console.ConsoleLineNotifier.connect(ConsoleLineNotifier.java:54)
	at org.eclipse.ui.internal.console.ConsolePatternMatcher.addPatternMatchListener(ConsolePatternMatcher.java:232)
	at org.eclipse.ui.console.TextConsole.addPatternMatchListener(TextConsole.java:409)
	at org.eclipse.debug.internal.ui.views.console.ProcessConsole.<init>(ProcessConsole.java:228)
	at org.eclipse.debug.internal.ui.views.console.ProcessConsoleManager.launchChanged(ProcessConsoleManager.java:149)
	at org.eclipse.debug.internal.core.LaunchManager$LaunchNotifier.run(LaunchManager.java:453)
	at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
	at org.eclipse.debug.internal.core.LaunchManager$LaunchNotifier.notify(LaunchManager.java:433)
	at org.eclipse.debug.internal.core.LaunchManager.fireUpdate(LaunchManager.java:1043)
	at org.eclipse.debug.core.Launch.fireChanged(Launch.java:393)
	at org.eclipse.debug.core.Launch.addProcess(Launch.java:355)
	at org.eclipse.debug.core.model.RuntimeProcess.<init>(RuntimeProcess.java:126)
	at org.eclipse.debug.core.DebugPlugin.newProcess(DebugPlugin.java:787)
	at org.eclipse.jdt.launching.AbstractVMRunner.newProcess(AbstractVMRunner.java:170)
	at org.eclipse.jdt.internal.launching.StandardVMRunner.run(StandardVMRunner.java:424)
	at org.jboss.ide.eclipse.as.wtp.core.server.launch.AbstractJavaServerLaunchDelegate.fireVMRunner(AbstractJavaServerLaunchDelegate.java:91)
	at org.jboss.ide.eclipse.as.wtp.core.server.launch.AbstractStartJavaServerLaunchDelegate.actualLaunch(AbstractStartJavaServerLaunchDelegate.java:95)
	at org.jboss.ide.eclipse.as.wtp.core.server.launch.AbstractStartJavaServerLaunchDelegate.launch(AbstractStartJavaServerLaunchDelegate.java:89)
	at org.jboss.tools.as.core.server.controllable.subsystems.internal.LocalJBossLaunchController.launch(LocalJBossLaunchController.java:94)
	at org.jboss.ide.eclipse.as.wtp.core.server.launch.ControllableServerLaunchConfiguration.launch(ControllableServerLaunchConfiguration.java:52)
	at org.eclipse.debug.internal.core.LaunchConfiguration.launch(LaunchConfiguration.java:885)
	at org.eclipse.debug.internal.core.LaunchConfiguration.launch(LaunchConfiguration.java:739)
	at org.eclipse.debug.internal.core.LaunchConfiguration.launch(LaunchConfiguration.java:731)
	at org.eclipse.wst.server.core.internal.Server.startImpl2(Server.java:3556)
	at org.eclipse.wst.server.core.internal.Server.startImpl(Server.java:3492)
	at org.eclipse.wst.server.core.internal.Server$StartJob.run(Server.java:367)
	at org.eclipse.core.internal.jobs.Worker.run(Worker.java:55)
Caused by: java.lang.ClassNotFoundException: org.jboss.ide.eclipse.freemarker.linetracker.ConsoleLineTracker cannot be found by org.jboss.ide.eclipse.freemarker_1.5.101.v20160714-1706
	at org.eclipse.osgi.internal.loader.BundleLoader.findClassInternal(BundleLoader.java:448)
	at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:361)
	at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:353)
	at org.eclipse.osgi.internal.loader.ModuleClassLoader.loadClass(ModuleClassLoader.java:161)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
	at org.eclipse.osgi.internal.framework.EquinoxBundle.loadClass(EquinoxBundle.java:564)
	at org.eclipse.core.internal.registry.osgi.RegistryStrategyOSGI.createExecutableExtension(RegistryStrategyOSGI.java:174)
	... 31 more

Plug-in org.jboss.ide.eclipse.freemarker was unable to load class org.jboss.ide.eclipse.freemarker.linetracker.ConsoleLineTracker.
java.lang.ClassNotFoundException: org.jboss.ide.eclipse.freemarker.linetracker.ConsoleLineTracker cannot be found by org.jboss.ide.eclipse.freemarker_1.5.101.v20160714-1706
	at org.eclipse.osgi.internal.loader.BundleLoader.findClassInternal(BundleLoader.java:448)
	at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:361)
	at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:353)
	at org.eclipse.osgi.internal.loader.ModuleClassLoader.loadClass(ModuleClassLoader.java:161)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
	at org.eclipse.osgi.internal.framework.EquinoxBundle.loadClass(EquinoxBundle.java:564)
	at org.eclipse.core.internal.registry.osgi.RegistryStrategyOSGI.createExecutableExtension(RegistryStrategyOSGI.java:174)
	at org.eclipse.core.internal.registry.ExtensionRegistry.createExecutableExtension(ExtensionRegistry.java:905)
	at org.eclipse.core.internal.registry.ConfigurationElement.createExecutableExtension(ConfigurationElement.java:243)
	at org.eclipse.core.internal.registry.ConfigurationElementHandle.createExecutableExtension(ConfigurationElementHandle.java:55)
	at org.eclipse.debug.internal.ui.views.console.ProcessConsoleManager.getLineTrackers(ProcessConsoleManager.java:281)
	at org.eclipse.debug.internal.ui.views.console.ConsoleLineNotifier.connect(ConsoleLineNotifier.java:54)
	at org.eclipse.ui.internal.console.ConsolePatternMatcher.addPatternMatchListener(ConsolePatternMatcher.java:232)
	at org.eclipse.ui.console.TextConsole.addPatternMatchListener(TextConsole.java:409)
	at org.eclipse.debug.internal.ui.views.console.ProcessConsole.<init>(ProcessConsole.java:228)
	at org.eclipse.debug.internal.ui.views.console.ProcessConsoleManager.launchChanged(ProcessConsoleManager.java:149)
	at org.eclipse.debug.internal.core.LaunchManager$LaunchNotifier.run(LaunchManager.java:453)
	at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
	at org.eclipse.debug.internal.core.LaunchManager$LaunchNotifier.notify(LaunchManager.java:433)
	at org.eclipse.debug.internal.core.LaunchManager.fireUpdate(LaunchManager.java:1043)
	at org.eclipse.debug.core.Launch.fireChanged(Launch.java:393)
	at org.eclipse.debug.core.Launch.addProcess(Launch.java:355)
	at org.eclipse.debug.core.model.RuntimeProcess.<init>(RuntimeProcess.java:126)
	at org.eclipse.debug.core.DebugPlugin.newProcess(DebugPlugin.java:787)
	at org.eclipse.jdt.launching.AbstractVMRunner.newProcess(AbstractVMRunner.java:170)
	at org.eclipse.jdt.internal.launching.StandardVMRunner.run(StandardVMRunner.java:424)
	at org.jboss.ide.eclipse.as.wtp.core.server.launch.AbstractJavaServerLaunchDelegate.fireVMRunner(AbstractJavaServerLaunchDelegate.java:91)
	at org.jboss.ide.eclipse.as.wtp.core.server.launch.AbstractStartJavaServerLaunchDelegate.actualLaunch(AbstractStartJavaServerLaunchDelegate.java:95)
	at org.jboss.ide.eclipse.as.wtp.core.server.launch.AbstractStartJavaServerLaunchDelegate.launch(AbstractStartJavaServerLaunchDelegate.java:89)
	at org.jboss.tools.as.core.server.controllable.subsystems.internal.LocalJBossLaunchController.launch(LocalJBossLaunchController.java:94)
	at org.jboss.ide.eclipse.as.wtp.core.server.launch.ControllableServerLaunchConfiguration.launch(ControllableServerLaunchConfiguration.java:52)
	at org.eclipse.debug.internal.core.LaunchConfiguration.launch(LaunchConfiguration.java:885)
	at org.eclipse.debug.internal.core.LaunchConfiguration.launch(LaunchConfiguration.java:739)
	at org.eclipse.debug.internal.core.LaunchConfiguration.launch(LaunchConfiguration.java:731)
	at org.eclipse.wst.server.core.internal.Server.startImpl2(Server.java:3556)
	at org.eclipse.wst.server.core.internal.Server.startImpl(Server.java:3492)
	at org.eclipse.wst.server.core.internal.Server$StartJob.run(Server.java:367)
	at org.eclipse.core.internal.jobs.Worker.run(Worker.java:55)