Visual Basic for Applications Reference
Invalid use of Null (Error 94)
See Also Specifics
Null is a Variant subtype used to indicate that a data item contains no valid data. This error has the following cause and solution:
You are trying to obtain the value of a Variant variable or an expression that is Null. For example:
MyVar = Null For Count = 1 To MyVar . . . Next Count
Make sure the variable contains a valid value.
For additional information, select the item in question and press F1.