The version of Essentials you will find on dev.bukkit.org will not work for 1.8 or newer - it is no longer in development.
There are forks of Essentials for those who need it on newer Minecraft versions however - Two of which are stable enough that we would suggest them for use.
The first is Spigot-Essentials, which you can get from here: https://hub.spigotmc.org/jenkins/job/Spigot-Essentials/
- Build #9 is for 1.8
- Build #12 is for 1.8.3/1.8.8
- Build #13 is for 1.9-1.10.2
- Use the latest build for 1.11/1.11.2
Make sure that you only use the correct build and jars needed and upload them to the servers plugins folder via the Files > FTP File Access page of your control panel (same password as MultiCraft to log into the files).
The main four jars being the Essentials, EssentialsChat, EssentialsProtect and EssentialsSpawn jars - the rest are not needed unless you specifically need what they add, and we would suggest no using them otherwise (The main 4 will provide all of the common Essentials features).
The second fork, which is the one we would suggest using the most, is EssentialsX. You can find their resources here: https://www.spigotmc.org/resources/essentialsx.9089/
In general you should always be using the latest development builds of this plugin, which you can get here: https://ci.drtshock.net/job/essentialsx/
These will work for all servers from 1.8 to 1.11.2 - as long as all of the EssentialsX jars you upload are from the same build. As above only install the jars you need - the extras should not be added unless necessary.
Any older/incorrect Essentials jars that are currently installed should be removed first - as with all plugins there should never be duplicates installed as it will cause issues.
