Crash: java.lang.IllegalArgumentException: bad Base64 input character at 3493: 0 (decimal)

Minecraft Crash Report ----
// I'm sorry, Dave.

Time: 2016-06-16 21:30
Description: Rendering screen

java.lang.IllegalArgumentException: bad Base64 input character at 3493: 0 (decimal)
at io.netty.handler.codec.base64.Base64.decode(Base64.java:247)
at io.netty.handler.codec.base64.Base64.decode(Base64.java:197)
at io.netty.handler.codec.base64.Base64.decode(Base64.java:188)
at bhm.c(SourceFile:212)
at bhm.a(SourceFile:145)
at bed.a(SourceFile:25)
at bei.b(SourceFile:410)
at bei.a(SourceFile:210)
at bhj.a(SourceFile:295)
at bnz.a(SourceFile:1062)
at bcx.av(SourceFile:991)
at bcx.a(SourceFile:396)
at net.minecraft.client.main.Main.main(SourceFile:124)

A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

– Head –
Thread: Client thread
Stacktrace:
at io.netty.handler.codec.base64.Base64.decode(Base64.java:247)
at io.netty.handler.codec.base64.Base64.decode(Base64.java:197)
at io.netty.handler.codec.base64.Base64.decode(Base64.java:188)
at bhm.c(SourceFile:212)
at bhm.a(SourceFile:145)
at bed.a(SourceFile:25)
at bei.b(SourceFile:410)
at bei.a(SourceFile:210)
at bhj.a(SourceFile:295)

– Screen render details –
Details:
Screen name: bhj
Mouse location: Scaled: (263, 178). Absolute: (526, 411)
Screen size: Scaled: (512, 384). Absolute: (1024, 768). Scale factor of 2
Stacktrace:
at bnz.a(SourceFile:1062)
at bcx.av(SourceFile:991)
at bcx.a(SourceFile:396)
at net.minecraft.client.main.Main.main(SourceFile:124)

– System Details –
Details:
Minecraft Version: 1.10
Operating System: Windows XP (x86) version 5.1
Java Version: 1.8.0_25, Oracle Corporation
Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Oracle Corporation
Memory: 114264760 bytes (108 MB) / 207380480 bytes (197 MB) up to 1060372480 bytes (1011 MB)
JVM Flags: 6 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M
IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
Launched Version: 1.10
LWJGL: 2.9.4
OpenGL: GeForce 7600 GS/PCI/SSE2/3DNOW! GL version 2.0.3, NVIDIA Corporation
GL Caps: Using GL 1.3 multitexturing.
Using GL 1.3 texture combiners.
Using framebuffer objects because EXT_framebuffer_object is supported.
Shaders are available because ARB_shader_objects, ARB_vertex_shader, and ARB_fragment_shader are supported.
VBOs are available because OpenGL 1.5 is supported.

Using VBOs: Yes
Is Modded: Probably not. Jar signature remains and client brand is untouched.
Type: Client (map_client.txt)
Resource Packs:
Current Language: English (New Zealand)
Profiler Position: N/A (disabled)
CPU: 2x AMD Athlon(tm) 64 X2 Dual Core Processor 3800