Variable '<variablename>' is used before it has been assigned a value
Variable '<variablename>' is used before it has been assigned a value. A null reference exception could result at run time.
An application has at least one possible path through its code that reads a variable before any value is assigned to it.
If a variable has never been assigned a value, it holds the default value for its data type. For a reference data type, that default value is Nothing (Visual Basic). Reading a reference variable that has a value of Nothing can cause a NullReferenceException in some circumstances.
By default, this message is a warning. For more information on hiding warnings or treating warnings as errors, see Configuring Warnings in Visual Basic.
Error ID: BC42104
To correct this error
Check your control flow logic and make sure the variable has a valid value before control passes to any statement that reads it.
One way to guarantee that the variable always has a valid value is to initialize it as part of its declaration. See "Initialization" in Dim Statement (Visual Basic).
See Also
Tasks
Troubleshooting Variables in Visual Basic