How To Install Mohist On A Minecraft Server
Installing
To get plugins to work on 1.12.2 or above, for Minecraft Forge, you will can use Mohist.
1 Head to the Official Mohist Website.
2 You will now see a drop down on the right hand side for a Variety of Minecraft Versions. Find the one that you will need and download it.

4 Next, you will go to the File Manager on the Kinetic Panel & Upload the Mohist Jar you downloaded.

5 After, you will head to the Settings Page & put the Mohist Jars name there.

You should be able to now add plugins to your server.
If the plugins folder is not there, Start your server once to it can appear.
Potential Issues
World Corruption - Running Mods and Plugins can cause problems with your servers world, we always recommend utilizing our Backup Manager to have backups before you make any changes.
Moving To or From Arclight - If you wanting to do this, if you have plugins on your server and you are moving off of Arclight, some plugins will do more than expected placing things in the world for an example. With this, it's best to see what the plugin actually does before adding Arclight onto your server.
Stability - Arclight can be Unstable causing your server to randomly crash with no real cause. In some cases, it might be a mixture of the mods and plugins you are running on the server putting your server in a crash loop.