By default, MetaMod: Source will fail to load on a properly configured LS server upon startup. No errors will be generated, and your server will act like MM:S isn't even installed. Any Source mods not officially supported by MetaMod: Source fall victim to this issue. Fortunately, there's a very simple fix to this common problem.
Assuming MetaMod: Source has already been installed, click here to download a properly configured VDF file for MM:S (you may have to right-click on the link and use "Save Target As..." to save it onto your computer). This VDF file includes the correct path to Lethal Stigma's mod directory, "lethalstigma," and as such should solve any issues you are having getting MetaMod: Source to work. Simply place the file in your lethalstigma/addons folder of your LS server and you are good to go.
If you have any questions, please post them in the comments section of this tutorial and a member of the development team will get back to you as soon as possible. I hope this tutorial was helpful. Thanks for choosing Lethal Stigma!