New error in Console

19:15:44] [Server thread/WARN]: [MythicMobs] Task #11881 for MythicMobs v2.4.5 generated an exception
java.lang.NullPointerException
at java.util.concurrent.ConcurrentHashMap.get(Unknown Source) ~[?:1.8.0_91]
at net.elseland.xikage.MythicMobs.Skills.Mechanics.SkillSkill.cast(SkillSkill.java:39) ~[?:?]
at net.elseland.xikage.MythicMobs.Skills.SkillMechanic.executeMetaSkill(SkillMechanic.java:407) ~[?:?]
at...

New error in Console