I've used some of the leaked plugins that have been uploaded here, but it seems like I'm having some problems with them starting, or with their performance like when trying to start CustomGUI.jar leaked by @WifiSpy see what I get.
Also when Skript ( Ultimate Essentials Pro) starts it takes longer than the whole server , look what it gives :
Could not load 'plugins/CustomGUI.jar' in folder 'plugins' org.bukkit.plugin.InvalidPluginException: java.lang.UnsupportedClassVersionError: me/jacobculley/customgui/CustomGUI : Unsupported major.minor version 52.0 at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:135) ~[spigot-1.8.8.jar:git-Spigot-0359393-9a17f01] at org.bukkit.plugin.SimplePluginManager.loadPlugin(SimplePluginManager.java:329) ~[spigot-1.8.8.jar:git-Spigot-0359393-9a17f01] at org.bukkit.plugin.SimplePluginManager.loadPlugins(SimplePluginManager.java:251) [spigot-1.8.8.jar:git-Spigot-0359393-9a17f01] at org.bukkit.craftbukkit.v1_8_R3.CraftServer.loadPlugins(CraftServer.java:292) [spigot-1.8.8.jar:git-Spigot-0359393-9a17f01] at net.minecraft.server.v1_8_R3.DedicatedServer.init(DedicatedServer.java:198) [spigot-1.8.8.jar:git-Spigot-0359393-9a17f01] at net.minecraft.server.v1_8_R3.MinecraftServer.run(MinecraftServer.java:524) [spigot-1.8.8.jar:git-Spigot-0359393-9a17f01] at java.lang.Thread.run(Thread.java:745) [?:1.7.0_79] Caused by: java.lang.UnsupportedClassVersionError: me/jacobculley/customgui/CustomGUI : Unsupported major.minor version 52.0 at java.lang.ClassLoader.defineClass1(Native Method) ~[?:1.7.0_79] at java.lang.ClassLoader.defineClass(ClassLoader.java:800) ~[?:1.7.0_79] at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142) ~[?:1.7.0_79] at java.net.URLClassLoader.defineClass(URLClassLoader.java:449) ~[?:1.7.0_79] at java.net.URLClassLoader.access00(URLClassLoader.java:71) ~[?:1.7.0_79] at java.net.URLClassLoader.run(URLClassLoader.java:361) ~[?:1.7.0_79] at java.net.URLClassLoader.run(URLClassLoader.java:355) ~[?:1.7.0_79] at java.security.AccessController.doPrivileged(Native Method) ~[?:1.7.0_79] at java.net.URLClassLoader.findClass(URLClassLoader.java:354) ~[?:1.7.0_79] at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:101) ~[spigot-1.8.8.jar:git-Spigot-0359393-9a17f01] at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:86) ~[spigot-1.8.8.jar:git-Spigot-0359393-9a17f01] at java.lang.ClassLoader.loadClass(ClassLoader.java:425) ~[?:1.7.0_79] at java.lang.ClassLoader.loadClass(ClassLoader.java:358) ~[?:1.7.0_79] at java.lang.Class.forName0(Native Method) ~[?:1.7.0_79] at java.lang.Class.forName(Class.java:274) ~[?:1.7.0_79] at org.bukkit.plugin.java.PluginClassLoader.<init>(PluginClassLoader.java:64) ~[spigot-1.8.8.jar:git-Spigot-0359393-9a17f01] at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:131) ~[spigot-1.8.8.jar:git-Spigot-0359393-9a17f01] ... 6 more"]
Also when Skript ( Ultimate Essentials Pro) starts it takes longer than the whole server , look what it gives :
[Server thread/WARN]: [Skript] Using an ID instead of an alias is discouraged and will likely not be supported in future versions of Skript anymore. Please replace '351:1' with e.g. 'rosered'. (HomeGUI.sk, line 2323: format slot 5 of player with 351:1 named "%{DelHomeNameAdminGUI}%" to close then run [execute player command "delhomeadmin"]') [07:42:21] [Server thread/WARN]: [Skript] Using an ID instead of an alias is discouraged and will likely not be supported in future versions of Skript anymore. Please replace '166' with e.g. 'barrier'. (HomeGUI.sk, line 2352: format slot 10 of player with 166 named "%{RemoveFriendsIconName}%" with lore "%{RemoveFriendsIconLore}%" to close then run [execute player command "homeguifriendremove"]') [07:43:09] [Server thread/WARN]: [Skript] Possible name conflict of variables {motd.line.1} and {motd.line.%arg 2%} (there might be more conflicts). (UE Pro (1.8.x).sk, line 2495: replace all "<totalplayers>" in {motd.line.1} with "%{_totalplayers}%"') [07:43:09] [Server thread/WARN]: [Skript] Possible name conflict of variables {motd.line.2} and {motd.line.%arg 2%} (there might be more conflicts). (UE Pro (1.8.x).sk, line 2496: replace all "<totalplayers>" in {motd.line.2} with "%{_totalplayers}%"') [07:43:26] [Server thread/ERROR]: [Skript] A command with the name /clearhome is already defined in HomeGUI.sk (UE Pro (1.8.x).sk, line 3114: command /clearhome [<offlineplayer>]:') [07:43:26] [Server thread/ERROR]: [Skript] undefined option {@warplistnoperm1} (UE Pro (1.8.x).sk, line 3147: message "{@warplistnoperm1}" to player') [07:43:26] [Server thread/ERROR]: [Skript] undefined option {@warplistnoperm2} (UE Pro (1.8.x).sk, line 3148: message "{@warplistnoperm2}" to player') [07:43:26] [Server thread/ERROR]: [Skript] undefined option {@warpsuccess} (UE Pro (1.8.x).sk, line 3153: message "{@warpsuccess}" to player') [07:43:26] [Server thread/ERROR]: [Skript] undefined option {@timewarp} (UE Pro (1.8.x).sk, line 3154: wait {@timewarp} seconds') [07:43:26] [Server thread/ERROR]: [Skript] '{@timewarp} seconds' is not a time span (UE Pro (1.8.x).sk, line 3154: wait {@timewarp} seconds') [07:43:26] [Server thread/ERROR]: [Skript] undefined option {@nowarp1} (UE Pro (1.8.x).sk, line 3160: message "{@nowarp1}" to player') [07:43:26] [Server thread/ERROR]: [Skript] undefined option {@nowarp2} (UE Pro (1.8.x).sk, line 3161: message "{@nowarp2}" to player') [07:43:50] [Server thread/WARN]: [Skript] Possible name conflict of variables {ue.deathchest.loc::%loop-index%} and {ue.deathchest.loc::*} (there might be more conflicts). (UE Pro (1.8.x).sk, line 4801: delete {ue.deathchest.loc::%loop-index%}') [07:44:03] [Server thread/INF"][Server thread/WARN]: [Skript] Using an ID instead of an alias is discouraged and will likely not be supported in future versions of Skript anymore. Please replace '351:1' with e.g. 'rosered'. (HomeGUI.sk, line 2323: format slot 5 of player with 351:1 named "%{DelHomeNameAdminGUI}%" to close then run [execute player command "delhomeadmin"]') [07:42:21] [Server thread/WARN]: [Skript] Using an ID instead of an alias is discouraged and will likely not be supported in future versions of Skript anymore. Please replace '166' with e.g. 'barrier'. (HomeGUI.sk, line 2352: format slot 10 of player with 166 named "%{RemoveFriendsIconName}%" with lore "%{RemoveFriendsIconLore}%" to close then run [execute player command "homeguifriendremove"]') [07:43:09] [Server thread/WARN]: [Skript] Possible name conflict of variables {motd.line.1} and {motd.line.%arg 2%} (there might be more conflicts). (UE Pro (1.8.x).sk, line 2495: replace all "<totalplayers>" in {motd.line.1} with "%{_totalplayers}%"') [07:43:09] [Server thread/WARN]: [Skript] Possible name conflict of variables {motd.line.2} and {motd.line.%arg 2%} (there might be more conflicts). (UE Pro (1.8.x).sk, line 2496: replace all "<totalplayers>" in {motd.line.2} with "%{_totalplayers}%"') [07:43:26] [Server thread/ERROR]: [Skript] A command with the name /clearhome is already defined in HomeGUI.sk (UE Pro (1.8.x).sk, line 3114: command /clearhome [<offlineplayer>]:') [07:43:26] [Server thread/ERROR]: [Skript] undefined option {@warplistnoperm1} (UE Pro (1.8.x).sk, line 3147: message "{@warplistnoperm1}" to player') [07:43:26] [Server thread/ERROR]: [Skript] undefined option {@warplistnoperm2} (UE Pro (1.8.x).sk, line 3148: message "{@warplistnoperm2}" to player') [07:43:26] [Server thread/ERROR]: [Skript] undefined option {@warpsuccess} (UE Pro (1.8.x).sk, line 3153: message "{@warpsuccess}" to player') [07:43:26] [Server thread/ERROR]: [Skript] undefined option {@timewarp} (UE Pro (1.8.x).sk, line 3154: wait {@timewarp} seconds') [07:43:26] [Server thread/ERROR]: [Skript] '{@timewarp} seconds' is not a time span (UE Pro (1.8.x).sk, line 3154: wait {@timewarp} seconds') [07:43:26] [Server thread/ERROR]: [Skript] undefined option {@nowarp1} (UE Pro (1.8.x).sk, line 3160: message "{@nowarp1}" to player') [07:43:26] [Server thread/ERROR]: [Skript] undefined option {@nowarp2} (UE Pro (1.8.x).sk, line 3161: message "{@nowarp2}" to player') [07:43:50] [Server thread/WARN]: [Skript] Possible name conflict of variables {ue.deathchest.loc::%loop-index%} and {ue.deathchest.loc::*} (there might be more conflicts). (UE Pro (1.8.x).sk, line 4801: delete {ue.deathchest.loc::%loop-index%}') [07:44:03] [Server thread/INF"]