Explaination Needed Please, ' Warning could '

Fellow RueSuite, Was testing some client work and was wondering if anyone could explain this please,

Kind regards

[client]: client frame initialized...
Map Amount 317+: 660
Map Amount: 660
Loaded Obj: 22323 Old items 21436
NPC.DAT : 1489108188
NPC.IDX : 1489126980
602 NPC Amount: 11257
Mapdata Region: 112
Mapdata Region: 113
Mapdata Region: 114
Mapdata Region: 115
Mapdata Region: 624
Mapdata Region: 625
Mapdata Region: 626
Mapdata Region: 627
java.lang.ArrayIndexOutOfBoundsException: 40
	at client.parsePacket(client.java:13712)
	at client.mainGameProcessor(client.java:3488)
	at client.processGameLoop(client.java:2747)
	at RSApplet.run(RSApplet.java:150)
	at client.run(client.java:5280)
	at java.lang.Thread.run(Unknown Source)
k: 3900, j: 19, i1: 11698
k: 3900, j: 7, i1: 20171
Mar 29, 2018 4:45:08 AM java.util.prefs.WindowsPreferences <init>
WARNING: Could not open/create prefs root node Software\JavaSoft\Prefs at root 0x80000002. Windows RegCreateKeyEx(...) returned error code 5.