Attempted to add FE to mods for an existing server set up, forgeessentials-1.10.2-10.1.113-server.jar Error I got was:

[12:43:50] [Server thread/INFO] [STDERR]: [com.forgeessentials.permissions.persistence.SingleFileProvider:load:44]: java.io.FileNotFoundException: ./world/FEData/permissions.json (No such file or directory)

The named file did not exist as the error stated. Tried a new server set up with just FE, that worked fine. Through process of elimination I found that FE (both 113 and 116 builds) fails when used with UndergroundBiomesConstructs-1.10-1.0.v.19.jar (found at http://www.minecraftforum.net/forums/mapping-and-modding/minecraft-mods/1293503-underground-biomes-constructs ).

On a lark, I tried running a FE alone at server start, removing all the world data except the FEData folder, adding UnergoundBiomesConstructs back in the mods. That just ended up with a new series of permissions problems.

MC 1.10.2
forge-1.10.2-12.18.3.2254

I can provide more info (specific full logs or whatever) if you need them.

Please download the latest build from http://ci.forgeessentials.com/job/FE-1.10/

Keep in mind FE for 1.10 is still alpha.

In the OP: I tried both 113 and 116 builds (latest on link you provided is 116).

As we moved to 1.12.2, is this still an issue? Closing this issue in 7 days if no response @Maccool