Yesterday, After updating Metasploit I got an error that Metasploit could not load some modules.
Metasploit Module could not be loaded : 
I think some modules are not completed when I'm doing update. So I will restore the modules named "outlook.rb"
1. Delete the related modules (in this case outlook.rb)
sudo rm -rf /opt/metasploit/msf3/modules/post/windows/gather/credentials/outlook.rb* 
2. Update the Metasploit with msfupdate command
sudo msfupdate 
3. Re-open your Metasploit and Horray the problem Fixed!
Note: In the other cases, if you found that some modules could not be loaded, you can use this trick by deleting the unloaded modules and restore it agains.