Minecraft: Minecraft 1.2.1

java.lang.NullPointerException
at java.io.Reader.<init>(Reader.java:78)
at java.io.InputStreamReader.<init>(InputStreamReader.java:97)
at adi.a(SourceFile:62)
at adi.a(SourceFile:99)
at net.minecraft.client.Minecraft.a(SourceFile:256)
at net.minecraft.client.Minecraft.run(SourceFile:650)
at java.lang.Thread.run(Thread.java:745)
— END ERROR REPORT 51cbac12 ----------