Unexpected runtime error

The runtime has encountered an unexpected error.

Error source

Page Name:/index.xsp
Control Id: _id19

Exception

Error while executing JavaScript computed expression
Script interpreter error, line=1, col=124: 'nadzaglavia.getDocumentByKey()' is null

JavaScript code

   1: print('asdasd: '+requestScope.issue);'?issue=2014-06&article='+nadzaglavia.getDocumentByKey(requestScope.issue+'|Позиция').getUniversalID()

Stack Trace