Thread: [Z508] Client crash on login

So my problem is, when i login on my client it just flashes white fast then crashes, it happens most of the time, but sometimes i can just login normal.. And It doesn't say anything in the server CMD window either, please help

EDIT: and it says this in the client CMD window:

Code:

java.lang.NumberFormatException: For input string: "interfaces"
	at java.lang.NumberFormatException.forInputString(Unknown Source)
	at java.lang.Integer.paseInt(Unknown Source)
	at java.lang.Integer.paseInt(Unknown Source)
	at ModelLoader.loadArray(ModelLoader.java:28)
	at ModelLoader.(init)(ModelLoader.java:10)
	at Class1_Sub4.method115(Class1_Sub4.java:795)
	at Class116.method1715(Class116.java:726)
	at Class116.method1702(Class116.java:104)
	at Class 68_Sub20_Sub17.method1181(Class68_Sub20_Sub17.java:429)
	at Class 68_Sub8.method673(Class68_Sub8.java:96)
	at Class 68_Sub7.method670(Class68_Sub7.java:120)
	at Class61.method598(Class61.java:442)
	at client.method33(client.java:779)
	at Applet_Sub1.method30(Applet_Sub1.java:475)
	at Applet_Sub1.run(Applet_Sub1.java:152)
	at java.lang.Thread.run(Unknown Source)
error_game_crash
Shutdown complete - clean:true
_

And it isn't about client or the account, because I've tried many clients and different accounts.. what's the problem please, and the weird thing that sometimes it works but sometimes (mostly) it doesn't..