I'm writing a letter in LyX, and I want to choose a document class for it. (I don't like the default letter.)

Looking at Document -> Settings -> Document class, I see that most classes are "unavailable". For example, Unavailable: Letter (KOMA-script). How do I make those available?

I tried installing the koma-script package in the MiKTeX package manager, but it didn't help.


Here's the dialog I get when doing Reconfigure:

LyX: System reconfiguration failed

The system reconfiguration has failed. Default textclass is used but LyX may not be able to work properly.

Please reconfigure again if needed.


  • Go to tools and then choose reconfigure
    – user2478
    Nov 20, 2011 at 19:02
  • Windows XP, LyX 1.6.7. (Don't know what "TeX distribution" means or how I find it out.)
    – Ram Rachum
    Nov 20, 2011 at 19:03
  • Did you refresh the file name database? (General tab in MikTeX options.) Nov 20, 2011 at 19:04
  • It is okay you edited your answer with this details. Do the reconfigure and restart LyX
    – user2478
    Nov 20, 2011 at 19:04
  • @Torbjörn: The package manager of MiKTeX does it by default
    – user2478
    Nov 20, 2011 at 19:05

1 Answer 1


From the LyX Wiki, Trouble Configuring LyX (missing classes) with MikTeX:

MiKTeX can cause problems with the configure script in LyX if the "Install missing packages on-the-fly" option is checked. If you find that only a few classes are available in LyX under Windows, try disabling this option in the MiKTeX general options (mo.exe) and re-configuring LyX.

So start MiKTeX options (start menu or mo.exe) and choose No (rather not not "Ask me first") for the option "Install missing packages on-the-fly", as recommended in the MiKTeX 2.9 issues (actually for TeXnicCenter compatibility), valid also for MiKTeX 2.8. If necessary, install manually using the MiKTeX package manager, and reconfigure LyX.

Here's a screenshot of the options window:

MiKTeX options

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .