Error while compiling: DronePilot.cs(417,38): error CS1061: Type `BasePlayer' does not contain a definition for `serverInput' and no extension method `serverInput' of type `BasePlayer' could be found. Are you missing an assembly reference?

This would generally only be the case if your server isn't fully patched with Oxide. I would make sure you are on the latest verison of the plugin as well. The plugin seems to build fine on our end.