Ajwboss Linkseyi Mod Problems

java.lang.Exception: No more empty terrain sprite indices left!
	at ModLoader.getUniqueTerrainSpriteIndex(ModLoader.java:751)
	at ModLoader.getUniqueSpriteIndex(ModLoader.java:728)
	at ModLoader.addOverride(ModLoader.java:421)
	at mod_BossMod.load(mod_BossMod.java:144)
	at ModLoader.init(ModLoader.java:938)
	at ModLoader.addAllRenderers(ModLoader.java:185)
	at avy.<init>(RenderManager.java:87)
	at avy.<clinit>(RenderManager.java:14)
	at net.minecraft.client.Minecraft.a(SourceFile:260)
	at net.minecraft.client.Minecraft.run(SourceFile:516)