NullPointer Exception in Database block

NullPointer Exception in Database block

In this case, NullPoiter exception is generated due to which a Database block will have to reference another Database block as the DataStructure_Text of the first database block has extern. 
When the database block can't be accessed an error will be generated. 

VisualSim.kernel.util.IllegalActionException: .Database_Null_Pointer_Exception.Local_Database -->
java.lang.NullPointerException
  in .Database_Null_Pointer_Exception.DigitalSimulator
at VisualSim.simulators.de.kernel.DEDirector.fireVisualSim(Unknown Source)
at VisualSim.simulators.de.kernel.DEDirector.fire(Unknown Source)
at VisualSim.actor.CompositeActor.fire(Unknown Source)
at VisualSim.actor.Manager.iterate(Unknown Source)
at VisualSim.actor.Manager.execute(Unknown Source)
at VisualSim.actor.Manager.run(Unknown Source)
at java.lang.Thread.run(Thread.java:745)
at VisualSim.kernel.util.VisualSimThread.run(Unknown Source)


Solution: Make sure to have the block parameters are correct. and the corresponding the blocks exist/