Cause: An identifier being referenced as a function was not declared or actually represents another object (for example, it might have been declared as a procedure).
Action: Check the spelling and declaration of the identifier. Also confirm that the declaration is placed correctly in the block structure.
PLS-00222: no function with name 'name' exists in this scope:
It cannot find the 'function' specified. This may be a packaged or standalone function.
If the routine is spelt correctly then the clue to the problem may be the word 'function' in the error message. It is looking for a function as opposed to a procedure. Perhaps it is really a procedure but has been mis-called, i.e. with a return variable.