Null Pointer when using Outline view in Task Board

We do not know the specific issue that is triggering this. When it happens for a user, they are out of luck without an administrator changing the taskboard card limit to something very low, which lets them go into their taskboard and change from Outline mode back to normal mode.

Here is the error in the browser window:

An error occurred whilst rendering this message. Please contact the administrators, and inform them of this bug.

Details:
-------
org.apache.velocity.exception.MethodInvocationException: Invocation of method 'getReferenceStepBoard' in class com.pyxis.greenhopper.jira.boards.OrphanTaskBoard threw exception class java.lang.NullPointerException : null
at org.apache.velocity.runtime.parser.node.ASTIdentifier.execute(ASTIdentifier.java:193)
at org.apache.velocity.runtime.parser.node.ASTReference.execute(ASTReference.java:175)
at org.apache.velocity.runtime.parser.node.ASTReference.value(ASTReference.java:327)
at org.apache.velocity.runtime.parser.node.ASTGTNode.evaluate(ASTGTNode.java:49)
at org.apache.velocity.runtime.parser.node.ASTGTNode.value(ASTGTNode.java:91)
at org.apache.velocity.runtime.parser.node.ASTExpression.value(ASTExpression.java:51)
at org.apache.velocity.runtime.parser.node.ASTSetDirective.render(ASTSetDirective.java:95)
at org.apache.velocity.runtime.parser.node.ASTBlock.render(ASTBlock.java:55)
at org.apache.velocity.runtime.parser.node.ASTIfStatement.render(ASTIfStatement.java:70)
...