How to Add Mods:
Stop your server
2. Find a mod that you want on the workshop (eg. https://steamcommunity.com/sharedfiles/filedetails/?id=440847161)
3. copy the number at the end (for the example it would be 440847161)
4. Open your worlds sandbox.sbc file and find '<Mods
It should look like this,
<Mods />
6. Change it so that it looks like this (minus the square brackets):
<Mods>
<Mod>
<Name>45454565464.sbm</Name>
<PublishedFileId>45454565464</PublishedFileId>
</Mod>
</Mods>
For more than 1 mod it should look like this (Again minus the square brackets)
<Mods>
<Mod>
<Name>[number from step 3].sbm</Name>
<PublishedFileId>[number from step 2]</PublishedFileId>
</Mod>
<Mod>
<Name>[number from step 3].sbm</Name>
<PublishedFileId>[number from step 3]</PublishedFileId>
</Mod>
</Mods>
If you have done it correctly the mods will load up and your Sandbox.sbc file should look something like this
<Mods>
<Mod>
<Name>346536434.sbm</Name>
<PublishedFileId>346536434</PublishedFileId>
</Mod>
<Mod>
<Name>45745374.sbm</Name>
<PublishedFileId>45745374</PublishedFileId>
</Mod>
<Mod>
<Name>4564874336.sbm</Name>
<PublishedFileId>4564874336</PublishedFileId>
</Mod>
</Mods>
7. Make sure inside the file MedievalEngineers-Dedicated.cfg you have this setting set as false or the server will generate a new world on the restart and will reset the mods: <IgnoreLastSession>false</IgnoreLastSession>
8. Start the server