Unable to load node with id

I am facing an issue where I am now a days getting a very frequent error when there is a update in my neo which as below:

org.neo4j.graphdb.NotFoundException: Node 47643382 not found
at org.neo4j.kernel.impl.factory.GraphDatabaseFacade.getNodeById(GraphDatabaseFacade.java:228)
at org.neo4j.kernel.impl.factory.GraphDatabaseFacade$3.apply(GraphDatabaseFacade.java:526)
at org.neo4j.kernel.impl.factory.GraphDatabaseFacade$3.apply(GraphDatabaseFacade.java:522)
at org.neo4j.collection.primitive.PrimitiveLongCollections$14.next(PrimitiveLongCollections.java:746)
at org.neo4j.helpers.collection.ResourceClosingIterator.next(ResourceClosingIterator.java:76)
Caused by: org.neo4j.kernel.api.exceptions.EntityNotFoundException: Unable to load NODE with id 47643382.
... 76 common frames omitted

	Code is as below:

while (parentNodes.hasNext())
Node parentEntityNode = parentNodes.next();

The hasNext() method does return true and when it tries to fetch the node, it throws an error with just the node name and no label information too.

is there a way to resolve this?

Trying to understand what can be problem for the same so that I can fix this. Not sure if any entity being referred is missing/deleted. If its deleted how is it having the mapping to the deleted entity.

Can you post more complete code example?

That's the only code. I can show how what we are getting the parentNodes.

parentNodes = graphDb.findNodes(label,key,value);
while (parentNodes.hasNext())
Node parentEntityNode = parentNodes.next(); --In this line the code breaks and throws the exception.
//perform operations...