Some other things to check: a) you're using Open JDK 6.0, or Sun JDK, IBM JDK, or BEA JRockit version 5.0 or 6.0 b) you're using matching JVM and Eclipse version (32-bit or 64-bit) c) you're using a compatible stack of projects under JBoss Tools 3.0 (Web Tools 3, EMF 2.4, XSD 2.4, Eclipse 3.4, BIRT 2.3 (only required for JBoss BIRT feature)) See also: http://wiki.eclipse.org/IRC_FAQ#How_do_I_start_Eclipse.3F http://wiki.eclipse.org/IRC_FAQ#How_do_I_debug_Eclipse.3F_How_can_I_see_w... http://wiki.eclipse.org/IRC_FAQ#I.27m_having_memory.2C_heap.2C_or_permgen... View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4197391#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...