When creating a formula using a Boolean field, use True, False, Yes, or No, without quotation marks.

Example: IF {CnBio.CnBio_Anonymous} = True THEN "Anonymous" ELSE {CnBio.CnBio_Name}

If the formula is giving this error but a Boolean field should not be used, check to make sure the formula has the correct fields.

For additional information and examples on formula functions, please go to Help, and Crystal Reports Help from within the Crystal Reports program.