Notepad++ is unable to load langs.xml, why?

Somehow, your langs.xml has errors in it. Perhaps while exploring various Notepad++ options you accidentally made unintended changes to it. That's what happened to me.

Go to the installation folder for Notepad++ and rename langs.xml to langs.xml.bad. Then, in that same folder, find langs.model.xml, make a copy of it, and rename the copy to langs.xml. DO NOT simply rename the file or you will not have it available the next time you need it.

also replace this file in the folder C:\users\(user)\appdata\roaming\notepad++

You will want to then compare the langs.xml to langs.xml.bad and see if there is anything legitimate that you want back.

If you are missing the langs.model.xml file, you can download the current version from the svn repo.

I had the same problem but I had to replace the langs.xml in the following path to fix it.

C:\Users\<username>\AppData\Roaming\Notepad++

For those on a current Windows release:

%appdata%\Notepad++ 

I had the same error message, but a different issue - the langs.xml file was OK. Replacing it with langs.model.xml did not fix the problem.

To fix the problem, I had to open langs.xml in Notepad++ (running as Admin on Windows7 to be able to save in ProgramFiles). Then, from the Encoding menu, I saw the file is saved as ANSI. The XML declaration specifies 1252 charset. So I re-encoded the file by selecting Encoding -> Character sets -> Western european -> Windows-1252. Then I made a small change to the file and re-saved it.

I suspect this is related to the default codepage of the system.