Crash when hooking StringBuilder

[zhengmin1989]

new HookConfig(true, // set to true to enable the hook
"java.lang.StringBuilder", "append", new Class<?>[]{java.lang.String.class},
// class, method name, arguments
new StringBuilderHook(),
// instance of the implementation extending IntroHook (here in HookExampleInpl.java)
"StringBuilder Hook"),

I tried to hook the ``append'' method of StringBuilder, but the app crashed after hooking.
In addition, after hooking, the device cannot launch after rebooting. I also tried to hook the "equals"
method of "java.lang.String", it worked fine. So please check the StringBuilder class hooking.