Message Oracle PLS-00498 - illegal use of a type before its declaration

ERRORillegal use of a type before its declaration
CAUSEA variable or constant was declared to be of a type whose declaration appears later in the compilation unit; or, a type or subtype was declared in terms of another type whose declaration appears later in the compilation unit.
ACTIONEnsure that the type declaration preceeds its use in the variable/ constant/type declaration.