Inappropriate unary use of an operator
What happened
You attempted to save a formula that HCL Notes® can't accept. A unary operator is an operator, such as - (negative), which can use only one operand. Your formula contains a binary operator, such as *, which requires at least two operands.
What you can do
Edit your formula to contain at least two operands.
If you're not designing an application, notify the application designer or manager about the error.