Visual Basic for Applications Reference
Division by zero (Error 11)
Specifics
Division by zero isn't possible. This error has the following cause and solution:
The value of an expression being used as a divisor is zero.
Check the spelling of variables in the expression. A misspelled variable name can implicitly create a numeric variable that is initialized to zero. Check previous operations on variables in the expression, especially those passed into the procedure as argument from other procedures.
For additional information, select the item in question and press F1.