Help

[K4TRIN4]

What does this exception mean and how do i fix it thanks
6/21/2013 10:46:39 PM: System.InvalidCastException: Specified cast is not valid.
at ns0.Class59.smethod_1(DataRow dataRow_0, String string_0, Class16 class16_0, Class12 class12_0) in C:\Documents and Settings\Kenny\Desktop\Phoenix v3.11.0 (14986)\Source\ns0\Class59.cs:line 23
at ns0.Class59.smethod_0(String string_0, Class16 class16_0, Class12 class12_0, Class12 class12_1) in C:\Documents and Settings\Kenny\Desktop\Phoenix v3.11.0 (14986)\Source\ns0\Class59.cs:line 9
at ns0.Class16.method_6(String string_0) in C:\Documents and Settings\Kenny\Desktop\Phoenix v3.11.0 (14986)\Source\ns0\Class16.cs:line 87