Object reference not set to an instance- Blueprism error

I have installed BP 6.10 and when i am trying to evaluate the expression from a collection,i get a error stating :
"System.NullReferenceException: Object reference not set to an instance of an object."

I am having values in collection (current values) .
1.jpg :showing the data item.collection and Looped collection
2.jpg :showing decision calculation
3.jpg : Error popped up when evaluated expression.

Error Details:
System.NullReferenceException: Object reference not set to an instance of an object.
at AutomateUI.frmExpressionTest.MakeRow(IDataField item, Int32 top, Int32 tabIndex, Int32 scrollbarAdj)
at AutomateUI.frmExpressionTest.Populate()
at AutomateUI.frmExpressionTest..ctor(Control owner, clsProcess proc, String expr, clsProcessStage stage, String name)
at AutomateUI.ctlProcessExpressionBuilder.TestExpression(String localExpr)

Can any expert please help me out here


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New Member
If you try to access a member of a class (here MyClass) then you get a System.NullReferenceException. Which is the same as "object reference not set to an instance of an object" . It indicates that you are trying to access member fields, or function types, on an object reference that points to null. That means the reference to an Object which is not initialized. To prevent the error, objects that could be null should be tested for null before being used.

if (mClass != null)
// Go ahead and use mClass
mClass.property = ...
// Whoops! mClass is null and cannot be used without first assigning it to an instance reference
// Attempting to use mClass here will result in NullReferenceException