Emmet - Notepad++ "Unknown exception"

I had the same problem as you.This is the solution which worked for me:

• emmetio/npp Bug ID #12: python script plugin did not accept the script

Basically, the problem lies in the Python Script plugin which will be automatically installed with Emmet.

Go to this link:
http://sourceforge.net/projects/npppythonscript/files/Python%20Script%200.9.2.0/
and download PythonScript_full_0.9.2.0 package.

Replace Notepad++'s Python package with PythonScript_full_0.9.2.0 and unpack the archive in Notepad++'s MAIN directory. (This is where notepad++.exe is.)
(Do NOT unpack the archive inside the plugins directory. That will not work. The python27.dll file needs to be in the same directory where notepad++.exe is.)

I am using Notepad++ v6.6.9 and it works now.

There is a newer version (PythonScript_1.0.8.0.msi ) available here:

http://sourceforge.net/projects/npppythonscript/files/latest/download?source=files

I had the exact same issue on two different computers, one Windows 7 and one Windows 8, both 64bit. I installed the MSI on the Win8 computer and it fixed the problem.

Check to see if it might be just the shortcut keys that aren't working by going to menuBar>plugins>emmet>expandAbbreviation. If clicking on that works after typing in some emmet syntax, but not when you type the shortcut key, reassign the shortcut keys. Here's what I did:

Look specifically at menuBar>settings>shortcutMapper

under Main Menu-> "Insert Blank Line Above Current"

and see that ctrl+alt+enter is already assigned there.

Change that to something else (I did ctrl+alt+up), and you'll see that your shortcut keys are working for emmet.