Problem: After creating a seam project, open the ".xhtml" made problem: Unhandled event loop exception Can't start the AWT because Java was started on the first thread. Make sure StartOnFirstThread is not specified in your application's Info.plist or on the command line Solution: edit your eclipse.ini ####### eclipse/Eclipse.app/Contents/MacOs/eclipse.ini #################### | | -showsplash | org.eclipse.platform | -vmargs | -Xdock:icon=../Resources/Eclipse.icns | -XstartOnFirstThread | -Xms40m | -Xmx512m | -XX:MaxPermSize=256m | -Dosgi.requiredJavaVersion=1.5 | -Dorg.eclipse.swt.internal.carbon.smallFonts remove the -XstartOnFirstThread and set this -Djava.awt.headless=true ####### eclipse/Eclipse.app/Contents/MacOs/eclipse.ini #################### | -showsplash | org.eclipse.platform | -vmargs | -Xdock:icon=../Resources/Eclipse.icns | -Djava.awt.headless=true | -Xms40m | -Xmx512m | -XX:MaxPermSize=256m | -Dosgi.requiredJavaVersion=1.5 | -Dorg.eclipse.swt.internal.carbon.smallFonts and then restart your eclipse View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4113729#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...