Problema con el SET (social engineer toolkit)

De antemano os pido las gracias por leer, mi problema es el siguiente: instale en ubuntu 11.01 el metasploit y luego el SET. El problema surge en que cuando quiero hacer el Java Applet Attack Method – (Backdorizacion con SET by ANTRAX) cuando llego a la creacion del ejecutable me aparece lo sig.:

Backdooring a legit executable to bypass Anti-Virus. Wait a few seconds...
/opt/metasploit/apps/pro/msf3/lib/fastlib.rb:374:in `fastlib_original_require': no such file to load -- active_support/concern (LoadError)
   from /opt/metasploit/apps/pro/msf3/lib/fastlib.rb:374:in `require'
   from /opt/metasploit/apps/pro/msf3/lib/msf/core/module_manager/cache.rb:4
   from /opt/metasploit/apps/pro/msf3/lib/fastlib.rb:374:in `fastlib_original_require'
   from /opt/metasploit/apps/pro/msf3/lib/fastlib.rb:374:in `require'
   from /opt/metasploit/apps/pro/msf3/lib/msf/core/module_manager.rb:27
   from /opt/metasploit/apps/pro/msf3/lib/fastlib.rb:374:in `fastlib_original_require'
   from /opt/metasploit/apps/pro/msf3/lib/fastlib.rb:374:in `require'
   from /opt/metasploit/apps/pro/msf3/lib/msf/core/framework.rb:66
   from /opt/metasploit/apps/pro/msf3/lib/fastlib.rb:374:in `fastlib_original_require'
   from /opt/metasploit/apps/pro/msf3/lib/fastlib.rb:374:in `require'
   from /opt/metasploit/apps/pro/msf3/lib/msf/core.rb:34
   from /opt/metasploit/apps/pro/msf3/lib/fastlib.rb:374:in `fastlib_original_require'
   from /opt/metasploit/apps/pro/msf3/lib/fastlib.rb:374:in `require'
   from /opt/metasploit/apps/pro/msf3/lib/msf/ui/console/driver.rb:2
   from /opt/metasploit/apps/pro/msf3/lib/fastlib.rb:374:in `fastlib_original_require'
   from /opt/metasploit/apps/pro/msf3/lib/fastlib.rb:374:in `require'
   from /opt/metasploit/apps/pro/msf3/lib/msf/ui/console.rb:11
   from /opt/metasploit/apps/pro/msf3/lib/fastlib.rb:374:in `fastlib_original_require'
   from /opt/metasploit/apps/pro/msf3/lib/fastlib.rb:374:in `require'
   from /opt/metasploit/apps/pro/msf3/lib/msf/ui.rb:11
   from /opt/metasploit/apps/pro/msf3/lib/fastlib.rb:374:in `fastlib_original_require'
   from /opt/metasploit/apps/pro/msf3/lib/fastlib.rb:374:in `require'
   from /opt/metasploit/apps/pro/msf3//msfpayload:61

• Backdoor completed successfully. Payload is now hidden within a legit executable.
  
• UPX Encoding is set to ON, attempting to pack the executable with UPX encoding.
  [-] Packing the executable and obfuscating PE file randomly, one moment.
  
  
  Something went wrong, printing the error: [Errno 2] No such file or directory: 'src/html/msf.exe'
  
  
  La verdad que no tengo ni idea de como arreglarlo, por favor les pido su ayuda. Desde ya muchas gracias.