getting exception when all errors/warnings are resolved

[05:51:07] error(10):  internal error: /Volumes/RAID Set 1/Downloads/pl_psm.g : java.lang.ArrayIndexOutOfBoundsException: Array index out of range: 337
java.util.Vector.get(Vector.java:694)
org.antlr.tool.Grammar.getTokenDisplayName(Grammar.java:2479)
org.antlr.codegen.CodeGenerator.genTokenTypeNames(CodeGenerator.java:863)
org.antlr.codegen.CodeGenerator.genRecognizer(CodeGenerator.java:431)
org.antlr.Tool.generateRecognizer(Tool.java:696)
org.antlr.Tool.process(Tool.java:509)
org.antlr.works.generate.CodeGenerate.generate(CodeGenerate.java:104)
org.antlr.works.generate.CodeGenerate.run(CodeGenerate.java:185)
java.lang.Thread.run(Thread.java:695)