Fitnesse: Could not find or load main class -

when run test below error:

error: not find or load main class c:\growthedition.qa\fitnesse\fitsharp\runner.exe 

the runner in specified location. in suitesetup have defined test runner:

variable defined: test_runner=c:\growthedition.qa\fitnesse\fitsharp\runner.exe  

what causing issue, , how can resolve it?

many thanks, rahul dixit

please ignore. dont, know did differently, started working again.