Unhandled Exception

Can someone help me?
In my Master’s thesis I’m trying to work with the Optimo package, in a Dynamo + RSA + Revit workflow. But when I start the program this error appears:

Object reference not set to an instance of an object.

at ProtoCore.DSASM.Heap.RecursiveMark(StackValue root)
at ProtoCore.DSASM.Heap.SingleStep(Boolean forceGC)
at ProtoCore.DSASM.Heap.FullGC(IEnumerable1 gcroots, Executive exe) at ProtoScript.Runners.LiveRunner.ApplyUpdate() at ProtoScript.Runners.LiveRunner.CompileAndExecuteForDeltaExecution(List1 astList)
at ProtoScript.Runners.LiveRunner.SynchronizeInternal(GraphSyncData syncData)
at ProtoScript.Runners.LiveRunner.UpdateGraph(GraphSyncData syncData)
at Dynamo.Scheduler.UpdateGraphAsyncTask.HandleTaskExecutionCore()
at Dynamo.Scheduler.AsyncTask.Execute()