# Class LNCS in LyX doesn't work

I have the same problem as posted here: [How to Install an Unavailable Document Class for LyX on Windows

I want to install the unavailable class LNCS in Lyx 2.2.2. I've tryed those steps in the link but it still doesn't work. The Latex error message "File 'llncs.cls' not found" appears in Lyx when i run a template that uses LNCS class.

• Welcome to TeX SX! Did you refresh the F.N.D.B.? – Bernard Dec 25 '17 at 23:02
• `Alt+H C` (Menu Help > Customization), but I would use a true LaTeX editor. – Fran Dec 25 '17 at 23:38
• @Bernard Thanks, actually yes i've already refreshed FNDB and followed all the required steps in the link. – Hafidi Yousra Dec 26 '17 at 12:53
• @HafidiYousra: AS I don't have LyX, I can give only general advice. I think you might try to compile your code from a standard editor like TeXmaker of TeX studio, and see if it works. You'll have a detailed .log file. – Bernard Dec 26 '17 at 13:04
• Fine! Note that apckages which are not part of the distribution should nbe preferably installed in a `local root`, say `TeXMFlocal`, to be declared via `MiKTeX Settings`, `root` tab. – Bernard Dec 26 '17 at 13:35

I found the problem,

A little clarification for those who want to install a class in LyX. Please follow these steps that are mentioned in the previous link:

Step 0:

Quit LyX

Step 1:

Download `llncs2e.zip`, which contains `llncs.cls` and `llncsdoc.sty`. I just googled for a download link and got mine from here.

Step 2:

Copy those files to the folder `...\MiKTeX 2.7\tex\latex\lncs`, where `...\MiKTeX 2.7` is the folder in which MiKTeX is installed. On some systems, copy to `... \MiKTeX 2.7\texmf\latex\lncs`. The `lncs` folder will probably need to be created.

Mine was in `C:\Program Files (x86)\MiKTeX 2.9\tex\latex`, where I had to create the `lncs` folder (which requires admin privilege escalation). I extracted `llncs.cls` and `llncsdoc.sty` to this folder.

Step 3:

Run

``````texhash
``````

from the command line.

Step 4:

Run MiKTeX Settings. Press "Refresh FNDB" under General. Then, possibly, "Update Formats".

Step 5:

Open LyX and select Tools -> Reconfigure

Very straightforward

But be sure to put the `llncs.cls` and `llncsdoc.style` files in:

``````C:\Users\YOURUSERNAME\AppData\Roaming\MiKTeX\2.9\tex\latex\lncs
``````

PS. Create the folder `lncs` if it doesn't exist.

If you are using TexLive, put the llncs.cls in the following path:

`TEXLIVE_ROOT_PATH/YEAR/texmf-dist/tex/latex/llncs2e`

The YEAR is 2018 if you are using TexLive 2018.

Run `texhash`.

Open Lyx and 'Tools' -> 'Reconfigure'.

Now in 'Document' -> 'Settings' -> 'Document Class', you should be able to see `Lecture Notes in Comp. Science (LNCS)` in the drop-down list.