"NoClassDefFoundError" in my Plugin

Hey Guys. I'm developing a PvP Kits plugin. And in some events and functions, I'm goting this Crash, "NoClassDefFoundError", its happening in many classes of my project, sometimes this not happen, and sometimes this happen... I'm confuse, I dont know what this crashes mean... Can someone help me?

 

Can you show the code?

 

gabrielhowat
Line 81 of KitsShopGUI, something's up with that. I'd suggest posting your code. If KitsShopGUI is not your plugin, then you might not have that plugin in your plugin folder when trying to start your server (if yours or another plugin depends on it)

 

MrSparkzz
This is a class of my plugin, in that line is only a Bukkit Scheduler, but the error don't happens only in this class, and is not every time, sometimes I got that error, sometimes not... I can't post my code now because I'm in the cellphone

 

post code and error in plain text, image is not acceptable.

 

The error is not in my Code, at that line, is a plugin.getServer().getScheduler().scheduleSyncDelayedTask(new Runnable......)
The error is in the "new Runnable()", sometimes the error is in the ".scheduleSyncDelayedTask", the error not happens every time...

 

gabrielhowat in the jar, does com/SPART/Screen/KitsShopGUI$2.class exist?

 

fireblast709 Yeah, and the package of "MOTD$1.class" and "MOTD$2.class", normally the error happens with the KitsShopGui or with the MOTD