Unexpected runtime error

The runtime has encountered an unexpected error.

Error source

Page Name:/page.xsp
Control Id: docRevised

Exception

Error while executing JavaScript computed expression
Script interpreter error, line=1, col=29: Error calling method 'elementAt(number)' on java class 'java.util.Vector'
Array index out of range: 5

JavaScript code

   1: revisions.getColumnValues().elementAt(5).toString();

► Stack Trace