Oracle Message PLS-00330 - invalid use of type name or subtype name

ERRORinvalid use of type name or subtype name
CAUSEA datatype or subtype specifier was mistakenly used in place of a constant, variable, or expression. For example, the code might look like IF emp_count > number THEN ... -- illegal; NUMBER is a datatype specifier
ACTIONReplace the datatype or subtype specifier with a valid constant, variable, or expression.