This function, Is Error Other Than Not Available, tests whether a value, an expression, or contents of a referenced cell has an error other than not available (#N/A).
ISERR(cellreference)
ISERR(value)
ISERR(expression)
Specify a cell reference, a numeric or text value, or an expression for the argument.
Use this function to test the contents of a cell, a numeric or text value directly, or a function or expression.
This function returns TRUE if the value refers to an empty cell or to no data.
Accepts any data type for an argument. Returns Boolean (TRUE or FALSE) data.
ISERR(B12)
ISERR(R12C2)
ISERR(#N/A) gives the result FALSE
ISERR(#REF!) gives the result TRUE
ISERR(C14) gives the result TRUE if C14 contains a #NUM! error.