(15:55:50) | Couldn't find required plugin 'EMInterface' for 'EventManager', retrying..

(15:55:53) | Failed compiling 'EMInterface.cs':

(15:55:53) | 1. The type or namespace name 'EventManager' could not be found (are you missing a using directive or an assembly reference?) [CS0246]

(EMInterface 64 line 808)

(15:55:53) | 2. The name 'EventManager' does not exist in the current context [CS0103]

(EMInterface 93 line 73)

(15:55:53) | Warning! 'EventManager' uses UnityEngine.GameObject.FindObjectsOfType. That may cause significant performance drops, and/or server stalls. Report to the developer or use at your own discretion!

(15:55:53) | Couldn't find required plugin 'EMInterface' for 'EventManager', retrying..

hello, try this fix

 add that line into EMInterface.cs, and reload  EventManager.cs

  ------- 
namespace Oxide.Plugins
{
    using EventManagerEx;        // add this line
    [Info("EMInterface", "k1lly0u", "2.0.2")]
    [Description("Manages and provides user interface for event games")]
------