Instructions for installation reference JBT 4.0.1, not 4.1

http://www.jboss.org/teiiddesigner/downloads.html

If you prefer to install from the archive file, download the archive from http://sourceforge.net/projects/jboss/files/JBossTools/JBossTools4.0.x/jbosstools-4.0.1.Final.aggregate-Update-2013-03-27_16-17-05-B340.zip After downloading, click the Archive... button - then select the *.zip file that you just downloaded. Click OK.

That should point to the JBT 4.1 release, not the JBT 4.0.1 release:

http://sourceforge.net/projects/jboss/files/JBossTools/JBossTools4.1.x/jbosstools-Update-4.1.0.Final_2013-07-19_19-47-52-B380.zip (ass seen on http://www.jboss.org/tools/download/stable/4_1 )