오랜만에 마크 해보고 싶다고 생각해서 켜봤는데

      Minecraft has crashed!     
      ----------------------     

Minecraft has stopped running because it encountered a problem.

--- BEGIN ERROR REPORT 7cf3a456 --------
Generated 18. 12. 22 오후 7:41

Minecraft: Minecraft 1.2.5
OS: Windows 8.1 (amd64) version 6.3
Java: 1.8.0_51, Oracle Corporation
VM: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
LWJGL: 2.9.0
OpenGL: AMD Radeon R7 200 Series version 4.5.13474 Compatibility Profile Context 22.19.162.4, ATI Technologies Inc.

java.lang.NullPointerException
 at java.io.Reader.<init>(Reader.java:78)
 at java.io.InputStreamReader.<init>(InputStreamReader.java:97)
 at adn.a(SourceFile:62)
 at adn.a(SourceFile:99)
 at net.minecraft.client.Minecraft.a(SourceFile:262)
 at net.minecraft.client.Minecraft.run(SourceFile:657)
 at java.lang.Thread.run(Thread.java:745)
--- END ERROR REPORT 39ee0169 ----------

라고 뜨는데 어떻게 고치는지 알려주세요