I'm getting similar results - OSX 10.8.2 using Safari/Java x64 and Windows 7/Firefox17/Java 7 u10. The applet will start loading and give me a progress bar - as it reaches approximately 75% it switches to the grey screen and then nothing happens.
Looks like the same error in the Java console:
Java Plug-in 10.9.2.05
Using JRE version 1.7.0_09-b05 Java HotSpot(TM) 64-Bit Server VM
User home directory = /Users/Kade
----------------------------------------------------
c: clear console window
f: finalize objects on finalization queue
g: garbage collect
h: display this help message
l: dump classloader list
m: print memory usage
o: trigger logging
q: hide console
r: reload policy configuration
s: dump system and deployment properties
t: dump thread list
v: dump thread stack
x: clear classloader cache
0-5: set trace level to <n>
----------------------------------------------------
Match: beginTraversal
Match: digest selected JREDesc: JREDesc[version 1.6+, heap=-1--1, args=null, href=http://java.sun.com/products/autodl/j2se, sel=false, null, null], JREInfo: JREInfo for index 0:
platform is: 1.7
product is: 1.7.0_09
location is: http://java.sun.com/products/autodl/j2se
path is: /Library/Internet Plug-Ins/JavaAppletPlugin.plugin/Contents/Home/bin/java
args is:
native platform is: Mac OS X, x86_64 [ x86_64, 64bit ]
JavaFX runtime is: JavaFX 2.2.3 found at /Library/Internet Plug-Ins/JavaAppletPlugin.plugin/Contents/Home/
enabled is: true
registered is: true
system is: true
Match: ignoring maxHeap: -1
Match: ignoring InitHeap: -1
Match: digesting vmargs: null
Match: digested vmargs: [JVMParameters: isSecure: true, args: ]
Match: JVM args after accumulation: [JVMParameters: isSecure: true, args: ]
Match: digest LaunchDesc: null
Match: digest properties: []
Match: JVM args: [JVMParameters: isSecure: true, args: ]
Match: endTraversal ..
Match: JVM args final:
Match: Running JREInfo Version match: 1.7.0.09 == 1.7.0.09
Match: Running JVM args match: have:<> satisfy want:<>