Commands aren't working in console and on the serv

If I type in a command on the serv ,Nothing shows up and nothing happens although the ping is fine , but if I type it in the console , they say that the command was issued but still , nothing happens , pls help
my plugins : Color_Signs_Text.jar ColoredChat
CombatTagPlusEssentials Essentials.jar Essentials.txt EssentialsAntiBuild.jar EssentialsChat.jar EssentialsProtect.jar EssentialsSpawn.jar HolographicDisplays HolographicDisplays.jar NoWorldDownloaderPluginMetricsProtocolLib ProtocolLib.jar ServerSigns ServerSigns.jar SilkSpawners SilkSpawners.jar SkQuery.jar UpdaterWorldEditWorldGuardbStats combattagplus_1_2_3.jar mystery_spawners_2_9.jar noworlddownloader_1_7_1_11_100_free_customizable_1_0r1.jar oitc_multi_arena_1_8_3_1_12_5_2_9.jar serverlistplus_3_4_7.jar skRayFall-1.9.9.jar worldedit-bukkit-6.1.jar worldguard-6.1.jar