https://gyazo.com/d6083d9853889e56c0e576f39f701ba5

also

[10:15:57] [Server thread/INFO]: F64_Rx issued server command: /unmuteip Accumulating
[10:15:57] [Craft Scheduler Thread - 37/WARN]: Exception in thread "Craft Scheduler Thread - 37"
[10:15:57] [Craft Scheduler Thread - 37/WARN]: org.apache.commons.lang.UnhandledException: Plugin BanManager v5.8.0 generated an exception while executing task 13234
at org.bukkit.craftbukkit.v1_8_R3.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:56)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NullPointerException
at me.confuser.banmanager.bukkitutil.Message.replace(Message.java:24)
at me.confuser.banmanager.bukkitutil.Message.set(Message.java:30)
at me.confuser.banmanager.commands.UnmuteIpCommand$1.run(UnmuteIpCommand.java:85)
at org.bukkit.craftbukkit.v1_8_R3.scheduler.CraftTask.run(CraftTask.java:71)
at org.bukkit.craftbukkit.v1_8_R3.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:53)
... 3 more

Are you on the latest developer build?

im version 5.8.0

This should already be fixed in builds 41+

http://ci.frostcast.net/job/BanManager/

https://gyazo.com/5dce093a0e89ecb2fae3c8653dea25aa when i do muteip it does this

https://gyazo.com/4876c7e459b0a4761a38337fab386158

thanks

im using the latest dev build and this happens still
https://gyazo.com/14acf7488aa1567e49bad4d37c1847d9

Regenerate your messages.yml file. This only affects new users from v5.8.0.