I'm not sure I see where the error is. Double check the set_config that it is pointed to the correct msf directory.
Well in set_config previously was default /pentest/exploits/framework3, which i later changed to cd /opt/metasploit/msf3/ after this still same problem, then i located msfconsole through terminal
root@bt:~# locate msfconsole
/opt/metasploit/app/msfconsole
/opt/metasploit/apps/pro/msf3/msfconsole
/opt/metasploit/apps/pro/msf3/test/functional/framework/msfconsole_spec.rb
/opt/metasploit/msf3/msfconsole
/opt/metasploit/msf3/.svn/prop-base/msfconsole.svn-base
/opt/metasploit/msf3/.svn/text-base/msfconsole.svn-base
/opt/metasploit/msf3/documentation/msfconsole_rc_ruby_example.rc
/opt/metasploit/msf3/documentation/.svn/text-base/msfconsole_rc_ruby_example.rc.svn-base
/opt/metasploit/msf3/external/source/armitage/resources/msfconsole.style
/opt/metasploit/msf3/external/source/armitage/resources/.svn/text-base/msfconsole.style.svn-base
/opt/metasploit/msf3/test/functional/framework/msfconsole_spec.rb
/opt/metasploit/msf3/test/functional/framework/.svn/text-base/msfconsole_spec.rb.svn-base
/pentest/exploits/framework2/msfconsole
/pentest/exploits/framework2/docs/QUICKSTART.msfconsole
/usr/local/bin/msfconsole
/usr/share/applications/backtrack-metasploit-msfconsole.desktop
then once again i configure in SET DEFINE THE PATH TO METASPLOIT HERE, FOR EXAMPLE /pentest/exploits/framework3
METASPLOIT_PATH= /pentest/exploits/framework2/msfconsole.
still not working anymore, where could be the problem, i use Backtrack 5R2, metasploit v4.4.0-dev. any ideas ?