500 Internal Server Error

java.io.IOException: C:\application_file_data\com.unisystems.esye.Book.IndexFile.10096280.data (The system cannot find the file specified)
at org.simplistic.web.FileDataGetServlet.doGet(FileDataGetServlet.java:108)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:740)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at com.evermind[Oracle Application Server Containers for J2EE 10g (10.1.2.2.0)].server.http.ServletRequestDispatcher.invoke(ServletRequestDispatcher.java:834)
at com.evermind[Oracle Application Server Containers for J2EE 10g (10.1.2.2.0)].server.http.ServletRequestDispatcher.forwardInternal(ServletRequestDispatcher.java:340)
at com.evermind[Oracle Application Server Containers for J2EE 10g (10.1.2.2.0)].server.http.HttpRequestHandler.processRequest(HttpRequestHandler.java:830)
at com.evermind[Oracle Application Server Containers for J2EE 10g (10.1.2.2.0)].server.http.AJPRequestHandler.run(AJPRequestHandler.java:228)
at com.evermind[Oracle Application Server Containers for J2EE 10g (10.1.2.2.0)].server.http.AJPRequestHandler.run(AJPRequestHandler.java:133)
at com.evermind[Oracle Application Server Containers for J2EE 10g (10.1.2.2.0)].util.ReleasableResourcePooledExecutor$MyWorker.run(ReleasableResourcePooledExecutor.java:192)
at java.lang.Thread.run(Thread.java:534)